CN108289015B

CN108289015B - Method and equipment for sending HARQ-ACK/NACK (hybrid automatic repeat request/acknowledgement) and downlink transmission method and equipment

Info

Publication number: CN108289015B
Application number: CN201710910258.9A
Authority: CN
Inventors: 王轶; 张世昌; 李迎阳
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2017-01-09
Filing date: 2017-09-29
Publication date: 2023-04-07
Anticipated expiration: 2037-09-29
Also published as: KR102568176B1; EP3566378A1; US11831446B2; KR20190097296A; EP3566378A4; CN108289015A; US20190363840A1

Abstract

A method and device for transmitting HARQ-ACK/NACK and a downlink transmission method and device are provided. The method for transmitting HARQ-ACK/NACK comprises the following steps: the user equipment receives PDSCH and control signaling from a base station in a downlink time unit; the user equipment determines an uplink time unit for feeding back HARQ-ACK/NACK corresponding to the received PDSCH, the size of an HARQ-ACK/NACK code book corresponding to the uplink time unit and the position of the HARQ-ACK/NACK corresponding to each downlink time unit corresponding to the uplink time unit in the HARQ-ACK/NACK code book based on the control signaling; the user equipment generates the HARQ-ACK/NACK code book based on the size of the HARQ-ACK/NACK code book and the position of the HARQ-ACK/NACK corresponding to each downlink time unit corresponding to the uplink time unit in the HARQ-ACK/NACK code book; and the user equipment sends the HARQ-ACK/NACK code book in the uplink time unit. The invention can ensure that the user equipment can accurately judge the size and bit mapping of the HARQ-ACK code book under the condition that the HARQ-ACK feedback time is variable.

Description

Method and equipment for sending HARQ-ACK/NACK (hybrid automatic repeat request/acknowledgement) and downlink transmission method and equipment

Technical Field

The present invention relates to the field of mobile communications technologies, and in particular, to a method and an apparatus for transmitting HARQ (hybrid automatic repeat request) -ACK/NACK (acknowledgement/negative acknowledgement), and a downlink transmission method and an apparatus.

Background

With the rapid development of the information industry, especially the growing demand from the mobile internet and the internet of things (IoT), an unprecedented challenge is brought to future mobile communication technologies. As can be expected from international telecommunication union ITU's report ITU-R M. [ imt. Beyond 2020.Traffic ], by 2020, mobile traffic will increase nearly 1000 times in relation to 2010 (era 4G), and the number of user equipment connections will also exceed 170 billion, and will be even more dramatic as the vast number of IoT devices gradually permeates into mobile communication networks. To address this unprecedented challenge, the communications industry and academia have developed an extensive fifth generation mobile communications technology research (5G) facing the 2020. Future 5G frameworks and overall goals are currently discussed in ITU's report ITU-R M. [ imt.vision ], where the 5G demand landscape, application scenarios and various important performance indicators are specified. For the new requirements in 5G, ITU's report ITU-R M [ imt. User TECHNOLOGY tree ] provides information related to the technical trend of 5G, aiming at solving significant problems of significant improvement of system throughput, consistency of user experience, scalability to support IoT, latency, energy efficiency, cost, network flexibility, support of emerging services, flexible spectrum utilization, and the like. In 3GPP, work on the first phase of 5G is already in progress. To support more flexible scheduling, 3GPP decides to support variable HARQ-ACK feedback delay in 5G. In the existing LTE (long term evolution) system, the time for receiving HARQ-ACK uplink transmission from downlink data is fixed, for example, in an FDD (frequency division duplex) system, the time delay is 4 subframes, and in a TDD (time division duplex) system, a HARQ-ACK feedback time delay is determined for a corresponding downlink subframe according to uplink and downlink configurations. In a 5G system, whether FDD or TDD, the uplink time unit for which HARQ-ACK can be fed back is variable for a certain downlink time unit (e.g., downlink timeslot, or downlink mini-timeslot). For example, the HARQ-ACK feedback delay may be dynamically indicated through physical layer signaling, or different HARQ-ACK delays may be determined according to different services or user capabilities and other factors.

In 5G, when the HARQ-ACK delay is variable, even in an FDD system, it may occur that HARQ-ACK to be fed back in one uplink time unit is from downlink data of multiple downlink time units, and the number of HARQ-ACK downlink time units to be fed back is also variable, and the situation is often different for each UE. Compared with the existing TDD system, the starting position and the length of the bundling window for HARQ-ACK feedback are variable due to the variable HARQ-ACK time delay. In addition, in 5G, in addition to the HARQ-ACK feedback mechanism with transport block granularity in the existing LTE system, coding block-based HARQ-ACK feedback may also be used, so the total overhead of HARQ-ACK will increase. In order to achieve scheduling flexibility, HARQ-ACK feedback effectiveness, and balance of downlink control signaling overhead supporting HARQ-ACK, a new method for sending and receiving HARQ-ACK feedback is urgently needed.

Disclosure of Invention

The present invention is provided to solve at least the above problems and to provide at least the following advantages.

According to an aspect of the present invention, there is provided a method of transmitting HARQ-ACK/NACK, including: the user equipment receives a PDSCH (physical downlink shared channel) and a control signaling from a base station in a downlink time unit; the user equipment determines an uplink time unit for feeding back HARQ-ACK/NACK corresponding to the received PDSCH, the size of an HARQ-ACK/NACK code book corresponding to the uplink time unit and the position of the HARQ-ACK/NACK corresponding to each downlink time unit corresponding to the uplink time unit in the HARQ-ACK/NACK code book based on the control signaling; the user equipment generates the HARQ-ACK/NACK code book based on the size of the HARQ-ACK/NACK code book and the position of the HARQ-ACK/NACK corresponding to each downlink time unit corresponding to the uplink time unit in the HARQ-ACK/NACK code book; and the user equipment sends the HARQ-ACK/NACK code book in the uplink time unit.

The control signaling may be downlink scheduling signaling carried through a PDCCH (physical downlink control channel) or control signaling carried through a PDSCH.

The control signaling may include information about HARQ-ACK/NACK timing.

The information on the HARQ-ACK/NACK timing may be one of the following information: the information indicating the time difference from the downlink time unit where the PDSCH is located to the uplink time unit where the HARQ-ACK/NACK is fed back, the information indicating one or more uplink time units which are larger than or equal to the minimum time difference from the downlink time unit where the PDSCH is located to the uplink time unit where the HARQ-ACK/NACK is fed back and are closest to the minimum time difference, the information indicating one or more uplink time units which are larger than or equal to the minimum time difference from the downlink time unit where the PDSCH is located to the uplink time unit where the HARQ-ACK/NACK is fed back and contain the configured PUCCH, the information indicating time difference from the downlink time unit where the predefined PDSCH is located to the uplink time unit where the HARQ-ACK/NACK is fed back, and the information indicating one or more uplink time units which are larger than or equal to the time difference from the downlink time unit where the predefined PDSCH is located to the uplink time unit where the HARQ-ACK/NACK is fed back and are closest to the minimum time difference.

The bit number of the information of the HARQ-ACK/NACK timing is different for different DCIs. The DCI in the downlink control channel common search region and the DCI in the user-specific search region have different bit numbers of the HARQ-ACK/NACK timing information.

The time difference from the downlink time unit where the PDSCH is located to the uplink time unit where the HARQ-ACK/NACK is fed back is different for different downlink control signaling DCI. The time difference of DCI indication in the downlink control channel common search region is predefined by a standard, and the time difference of DCI indication in the user-specific search region is configured by a high layer. The control signaling may further include a first type of DAI (downlink assignment index) and/or a second type of DAI, where the first type of DAI indicates one of the following information: relative time sequence of the current scheduled downlink time unit in all the scheduled downlink time units corresponding to the uplink time unit, and bit position of HARQ-ACK/NACK bit of the current scheduled downlink time unit in the HARQ-ACK/NACK code book.

In the control signaling, the first type of DAI may be jointly encoded with information about HARQ-ACK/NACK timing.

Wherein the second type of DAI indicates one of the following information: the total number of downlink time units of all scheduled downlink time units corresponding to the uplink time unit, the total number of downlink time units from a first downlink time unit to a current downlink time unit in all scheduled downlink time units corresponding to the uplink time unit, and the total bit number of the second-type DAI indication HARQ-ACK/NACK codebook.

The control signaling may include a third type DAI, where content of the third type DAI indication is the same as that of the second type DAI indication, or the third type DAI indication indicates a total bit number of HARQ-ACK/NACK codebooks expected to be received by the base station, and the total bit number of HARQ-ACK/NACK corresponding to a PDSCH actually scheduled by the base station is less than or equal to the expected total bit number.

In the control signaling, the first type of DAI, the second type of DAI, and information on HARQ-ACK/NACK timing may be jointly encoded.

The determining of the size of the HARQ-ACK/NACK codebook corresponding to the uplink time unit may include: calculating the size of a feedback window based on the information about the HARQ-ACK/NACK timing, wherein the feedback window is a set of all downlink time units which are determined by all possible values of the HARQ-ACK timing and can feed back HARQ-ACK/NACK in the uplink time unit at the same time; and obtaining the size of the HARQ-ACK/NACK code book corresponding to the uplink time unit by combining the size of the feedback window and the number of HARQ-ACK/NACK bits corresponding to each downlink time unit.

The step of determining the size of the HARQ-ACK/NACK codebook corresponding to the uplink time unit may include one of the following steps: determining the size of the HARQ-ACK/NACK codebook by combining the maximum value in the first type DAI of all scheduled downlink time units corresponding to the uplink time unit and the HARQ-ACK/NACK bit number corresponding to each downlink time unit; under the condition that the second type of DAI indicates the total number of downlink time units of all scheduled downlink time units corresponding to the uplink time units, determining the size of the HARQ-ACK/NACK codebook by combining the value of the second type of DAI and the number of HARQ-ACK/NACK bits corresponding to each downlink time unit; under the condition that the second type DAI indicates the total number of downlink time units from a first downlink time unit to a current downlink time unit in all scheduled downlink time units corresponding to the uplink time unit, determining the size of the HARQ-ACK/NACK codebook by combining the maximum value in the second type DAI of all scheduled downlink time units corresponding to the uplink time unit and the number of HARQ-ACK/NACK bits corresponding to each downlink time unit; and determining the size of the HARQ-ACK/NACK code book based on the bit number indicated by the second type DAI under the condition that the second type DAI indicates the total bit number of the HARQ-ACK/NACK code book.

If the third type of DAI is indicated, the HARQ-ACK/NACK codebook is determined according to the first type of DAI, the second type of DAI and the third type of DAI together. If the values of the second class DAIs and the third class DAIs are not consistent, determining the size of the HARQ-ACK/NACK code book according to the third class DAIs, and determining the HARQ-ACK bit sequence in the code book at least according to the first class DAIs.

The number of HARQ-ACK/NACK bits corresponding to each downlink time unit may be predefined by a standard or configured semi-statically, where the number of HARQ-ACK/NACK bits corresponding to each downlink time unit is determined according to one of the following: the number of the most transmittable transmission blocks per downlink time unit, the number of the most transmittable coding blocks per downlink time unit, and the number of the most transmittable coding block groups per downlink time unit. Preferably, for a specific carrier, when the number of HARQ-ACK/NACK bits corresponding to each downlink time unit is configured according to the maximum number of coding block groups that can be transmitted in each downlink time unit, no matter whether scheduling signaling based on a transport block or scheduling signaling based on a coding block group is used for scheduling the downlink time unit, the HARQ-ACK/NACK bits are determined according to the number of coding block groups.

The control signaling may further include information indicating that the number of HARQ-ACK/NACK bits corresponding to each downlink time unit is determined according to the number of the most transmittable transmission blocks for each downlink time unit, or according to the number of the most transmittable coding block groups for each downlink time unit.

The control signaling may also include the size of the HARQ-ACK/NACK codebook configured by the base station.

The determining of the size of the HARQ-ACK/NACK codebook corresponding to the uplink time unit may include: determining a size of a HARQ-ACK/NACK codebook corresponding to the uplink time unit based on a size of the HARQ-ACK/NACK codebook configured by a base station.

The step of determining the position of the HARQ-ACK/NACK corresponding to each downlink time unit corresponding to the uplink time unit in the HARQ-ACK/NACK codebook may include: obtaining a minimum number of bits that the HARQ-ACK/NACK corresponding to each HARQ process can occupy by dividing the determined size of the HARQ-ACK/NACK codebook by a total number of HARQ processes that can be supported in one uplink time unit; and obtaining the starting point of the HARQ-ACK/NACK corresponding to each downlink time unit corresponding to the uplink time unit in the HARQ-ACK/NACK code book by multiplying the minimum bit number which can be occupied by the HARQ-ACK/NACK corresponding to each HARQ process by the ID (identifier) of the HARQ process of each downlink time unit corresponding to the uplink time unit.

The step of generating the HARQ-ACK/NACK codebook may include: generating HARQ-ACK/NACK according to the received PDSCH for the effective HARQ process, and inserting the HARQ-ACK/NACK generated for the effective HARQ process into the HARQ-ACK/NACK codebook based on the starting point of the HARQ-ACK/NACK corresponding to the downlink time unit corresponding to the effective HARQ process in the HARQ-ACK/NACK codebook; for an invalid HARQ process, generating HARQ-NACK according to a predefined rule, and inserting the HARQ-NACK generated for the invalid HARQ process into the HARQ-ACK/NACK codebook based on a starting point of the HARQ-ACK/NACK in the HARQ-ACK/NACK codebook corresponding to a downlink time unit corresponding to the invalid HARQ process.

The valid HARQ process may refer to an HARQ process in which a PDSCH is received in a downlink time unit corresponding to the uplink time unit and HARQ-ACK/NACK of the PDSCH is fed back in the uplink time unit, and the invalid HARQ process may refer to an HARQ process in which a PDSCH is not received in the downlink time unit corresponding to the uplink time unit and/or an HARQ process in which a PDSCH is received in the downlink time unit corresponding to the uplink time unit but HARQ-ACK/NACK of the PDSCH is not fed back in the uplink time unit, or the valid HARQ process may refer to an HARQ process in which a PDSCH is received in the downlink time unit corresponding to the uplink time unit and a time difference between the downlink time unit in which the PDSCH is located and the uplink time unit is greater than or equal to a predefined minimum time delay, and the invalid HARQ process may refer to an HARQ process in which a PDSCH is not received in the downlink time unit corresponding to the uplink time unit and/or a time difference between the downlink time unit in which the PDSCH is received in the downlink time unit corresponding to the uplink time unit and the predefined minimum time delay is less than the PDSCH, and/or an HARQ process in which an uplink time unit corresponding to the PDSCH is received but is fed back in the uplink time unit.

The step of inserting the HARQ-ACK/NACK generated for the active HARQ process into the HARQ-ACK/NACK codebook may include: when the bit number of the HARQ-ACK/NACK corresponding to the effective HARQ process is larger than the minimum bit number which can be occupied by the HARQ-ACK/NACK corresponding to each HARQ process, the HARQ-ACK/NACK corresponding to the effective HARQ process occupies the position of the HARQ-ACK/NACK corresponding to the next HARQ process, wherein the step of inserting the HARQ-NACK generated aiming at the invalid HARQ process into the HARQ-ACK/NACK codebook comprises the following steps: when the position of the HARQ-ACK/NACK corresponding to the invalid HARQ process is occupied by the HARQ-ACK/NACK corresponding to the valid HARQ process, determining the bit number of the HARQ-ACK/NACK corresponding to the invalid HARQ process as the difference between the minimum bit number which can be occupied by the HARQ-ACK/NACK corresponding to each HARQ process and the occupied bit number of the HARQ-ACK/NACK corresponding to the valid HARQ process.

The step of determining the position of the HARQ-ACK/NACK corresponding to each downlink time unit corresponding to the uplink time unit in the HARQ-ACK/NACK codebook may include: calculating downlink time unit indexes of the downlink time units corresponding to the uplink time units based on the information on the HARQ-ACK/NACK timing, wherein the downlink time unit indexes of the downlink time units corresponding to the uplink time units respectively represent the relative time sequence of the downlink time units corresponding to the uplink time units in a feedback window; obtaining the minimum bit number which can be occupied by the HARQ-ACK/NACK corresponding to each downlink time unit by dividing the size of the HARQ-ACK/NACK code book by the size of a feedback window; and obtaining the starting point of the HARQ-ACK/NACK corresponding to each downlink time unit corresponding to the uplink time unit in the HARQ-ACK/NACK codebook by multiplying the minimum bit number which can be occupied by the HARQ-ACK/NACK corresponding to each downlink time unit by the downlink time unit index of each downlink time unit corresponding to the uplink time unit.

The step of determining the position of the HARQ-ACK/NACK corresponding to each downlink time unit corresponding to the uplink time unit in the HARQ-ACK/NACK code book comprises the following steps: calculating the size of a feedback window based on the information about the HARQ-ACK/NACK timing, wherein the feedback window is a set of all downlink time units which are determined by all possible values of the HARQ-ACK timing and can feed back HARQ-ACK/NACK in the uplink time unit at the same time; determining downlink time unit indexes of the downlink time units corresponding to the uplink time units based on the information on the HARQ-ACK/NACK timing, wherein the downlink time unit indexes of the downlink time units corresponding to the uplink time units respectively represent relative time sequences of the downlink time units corresponding to the uplink time units in a feedback window; obtaining the minimum bit number which can be occupied by the HARQ-ACK/NACK corresponding to each downlink time unit by dividing the size of the HARQ-ACK/NACK code book by the size of a feedback window; and obtaining the starting point of the HARQ-ACK/NACK corresponding to each downlink time unit corresponding to the uplink time unit in the HARQ-ACK/NACK codebook by multiplying the minimum bit number which can be occupied by the HARQ-ACK/NACK corresponding to each downlink time unit by the downlink time unit index of each downlink time unit corresponding to the uplink time unit.

The control signaling may further include information indicating a time unit in which the PDSCH is not transmitted with certainty, wherein the step of calculating the size of the feedback window includes: calculating the size of a feedback window by subtracting the number of time units in which the PDSCH must not be transmitted from the calculated size of the feedback window, or maintaining the calculated size of the feedback window if information indicating the time units in which the PDSCH must not be transmitted is indicated through dynamic signaling; if the information indicating the time unit in which the PDSCH must not be transmitted is indicated through semi-static signaling, the size of the feedback window is calculated by subtracting the number of time units in which the PDSCH must not be transmitted from the size of the calculated feedback window.

The step of generating the HARQ-ACK/NACK codebook may include: generating HARQ-ACK/NACK according to the received PDSCH for the effective downlink time unit, and inserting the HARQ-ACK/NACK generated for the effective downlink time unit into the HARQ-ACK/NACK codebook based on a starting point of the HARQ-ACK/NACK corresponding to the effective downlink time unit in the HARQ-ACK/NACK codebook; generating HARQ-NACK according to a predefined rule for an invalid downlink time unit and inserting the generated HARQ-NACK for the invalid downlink time unit into the HARQ-ACK/NACK codebook based on a starting point of the HARQ-ACK/NACK in the HARQ-ACK/NACK codebook corresponding to the invalid downlink time unit, or generating HARQ-NACK according to a predefined rule for a downlink time unit for which the PDSCH is not received and inserting the generated HARQ-NACK into the HARQ-ACK/NACK codebook based on a position of the HARQ-ACK/NACK in the HARQ-ACK/NACK codebook corresponding to a downlink time unit for which the PDSCH is not received; generating HARQ-ACK/NACK according to the PDSCH aiming at the uplink time unit which receives the PDSCH but corresponds to the HARQ-ACK/NACK and is not the downlink time unit of the uplink time unit, and inserting the generated HARQ-ACK/NACK into the HARQ-ACK/NACK code book.

The valid downlink time element may refer to a downlink time element in which the PDSCH is received and the uplink time element of the HARQ-ACK/NACK corresponding to the PDSCH is the uplink time element, and the invalid downlink time element may refer to a downlink time element in which the PDSCH is not received or a downlink time element in which the PDSCH is not received but the uplink time element of the HARQ-ACK/NACK corresponding to the PDSCH is not the uplink time element.

The inserting of the HARQ-ACK/NACK generated for the valid downlink time unit into the HARQ-ACK/NACK codebook may include: when the number of bits of the HARQ-ACK/NACK corresponding to the valid downlink time unit is greater than the minimum number of bits that the HARQ-ACK/NACK corresponding to each downlink time unit can occupy, the HARQ-ACK/NACK corresponding to the valid downlink time unit occupies the position of the HARQ-ACK/NACK corresponding to the immediately following downlink time unit, wherein the step of inserting the HARQ-NACK generated for the invalid downlink time unit into the HARQ-ACK/NACK codebook may include: when the position of the HARQ-ACK/NACK corresponding to the invalid downlink time unit is occupied by the HARQ-ACK/NACK corresponding to the valid downlink time unit, determining the bit number of the HARQ-ACK/NACK corresponding to the invalid downlink time unit as the difference between the minimum bit number which can be occupied by the HARQ-ACK/NACK corresponding to each downlink time unit and the occupied bit number of the HARQ-ACK/NACK corresponding to the valid downlink time unit.

The step of determining the position of HARQ-ACK/NACK corresponding to each downlink time unit corresponding to the uplink time unit in the HARQ-ACK/NACK codebook may include: and determining the position of HARQ-ACK/NACK corresponding to each downlink time unit of all scheduled downlink time units corresponding to the uplink time unit in the HARQ-ACK/NACK code book based on the first class DAI values of all scheduled downlink time units corresponding to the uplink time unit.

The step of generating the HARQ-ACK/NACK codebook may include: and inserting HARQ-ACK/NACK corresponding to all the scheduled downlink time units in sequence from the initial position of the HARQ-ACK/NACK codebook according to the size of the relative time sequence indicated by the first type DAI of all the scheduled downlink time units corresponding to the uplink time unit, and inserting occupancy bits at the subsequent position.

The transmitting of the HARQ-ACK/NACK codebook may include: when the total bit number of the uplink control signaling at least containing HARQ-ACK/NACK needing to be fed back in the uplink time unit exceeds the maximum bit number of the uplink control signaling which can be carried by PUCCH resources configured by the base station, executing one of the following operations: compressing the bits of the HARQ-ACK/NACK which need to be fed back in the uplink time unit according to a predefined rule; using a next larger PUCCH resource capable of bearing the total bit number of the uplink control signaling to be fed back to send the uplink control signaling in the uplink time unit; receiving downlink scheduling information indicating a new PUCCH resource capable of bearing the total bit number of uplink control signaling to be fed back from a base station in a current downlink time unit or at least the last downlink time unit corresponding to the uplink time unit, and sending the uplink control signaling in the uplink time unit by using the new PUCCH resource; and giving up the sending of the HARQ-ACK/NACK of the downlink time unit with low priority, so that the total bit number of the sent uplink control signaling does not exceed the maximum bit number of the uplink control signaling which can be carried by the PUCCH resource configured by the base station.

According to another aspect of the present invention, a downlink transmission method is provided, including: the base station configures control signaling; the base station sends PDSCH and control signaling to the user equipment in a downlink time unit, wherein the control signaling is used for determining that the user equipment feeds back at least one of the following: an uplink time unit of HARQ-ACK/NACK corresponding to PDSCH, the size of an HARQ-ACK/NACK codebook corresponding to the uplink time unit, and the position of HARQ-ACK/NACK corresponding to each downlink time unit corresponding to the uplink time unit in the HARQ-ACK/NACK codebook.

According to another aspect of the present invention, there is provided an apparatus for transmitting HARQ-ACK/NACK, including: a reception unit which receives a PDSCH and a control signaling from a base station in a downlink time unit; a determining unit configured to determine, based on the control signaling, an uplink time unit for feeding back HARQ-ACK/NACK corresponding to the received PDSCH, a size of an HARQ-ACK/NACK codebook corresponding to the uplink time unit, and a position of HARQ-ACK/NACK corresponding to each downlink time unit corresponding to the uplink time unit in the HARQ-ACK/NACK codebook; a generating unit, configured to generate the HARQ-ACK/NACK codebook based on the size of the HARQ-ACK/NACK codebook and a position of HARQ-ACK/NACK corresponding to each downlink time unit corresponding to the uplink time unit in the HARQ-ACK/NACK codebook; and a transmitting unit for transmitting the HARQ-ACK/NACK code book in the uplink time unit.

The control signaling may be downlink scheduling signaling carried through a PDCCH or control signaling carried through a PDSCH.

The control signaling may include information about HARQ-ACK/NACK timing.

The information on the HARQ-ACK/NACK timing may be one of the following information: the information indicating the time difference from the downlink time unit where the PDSCH is located to the uplink time unit where the HARQ-ACK/NACK is fed back, the information indicating one or more uplink time units which are larger than or equal to the minimum time difference from the downlink time unit where the PDSCH is located to the uplink time unit where the HARQ-ACK/NACK is fed back and are closest to the minimum time difference, the information indicating the time difference from the downlink time unit where the predefined PDSCH is located to the uplink time unit where the HARQ-ACK/NACK is fed back, the information indicating one or more uplink time units which are larger than or equal to the minimum time difference from the downlink time unit where the PDSCH is located to the uplink time unit where the HARQ-ACK/NACK is fed back and are closest to the minimum time difference, and the information indicating one or more uplink time units which are larger than or equal to the time difference from the downlink time unit where the predefined PDSCH is located to the uplink time unit where the HARQ-ACK/NACK is fed back and are closest to the minimum time difference.

The control signaling may further include a first type of DAI, wherein the first type of DAI indicates one of the following information: relative time sequence of the current scheduled downlink time unit in all the scheduled downlink time units corresponding to the uplink time unit, and bit position of HARQ-ACK/NACK bit of the current scheduled downlink time unit in the HARQ-ACK/NACK code book.

The control signaling may also include a second type of DAI, wherein the second type of DAI indicates one of the following information: the total number of downlink time units of all scheduled downlink time units corresponding to the uplink time unit, the total number of downlink time units from a first downlink time unit to a current downlink time unit in all scheduled downlink time units corresponding to the uplink time unit, and the total bit number of the second-class DAI indication HARQ-ACK/NACK codebook.

The determining unit may calculate a size of a feedback window based on information about HARQ-ACK/NACK timing, wherein the feedback window is a set of all downlink time units that may feed back HARQ-ACK/NACK in the uplink time unit at the same time, determined by all possible values of the HARQ-ACK timing; and obtaining the size of the HARQ-ACK/NACK code book corresponding to the uplink time unit by combining the size of the feedback window and the number of HARQ-ACK/NACK bits corresponding to each downlink time unit.

The determination unit may perform one of the following steps: determining the size of the HARQ-ACK/NACK codebook by combining the maximum value in the first type DAI of all scheduled downlink time units corresponding to the uplink time unit and the HARQ-ACK/NACK bit number corresponding to each downlink time unit; under the condition that the second type of DAI indicates the total number of downlink time units of all scheduled downlink time units corresponding to the uplink time units, determining the size of the HARQ-ACK/NACK codebook by combining the value of the second type of DAI and the number of HARQ-ACK/NACK bits corresponding to each downlink time unit; under the condition that the second type of DAI indicates the total number of downlink time units from a first downlink time unit to a current downlink time unit in all scheduled downlink time units corresponding to the uplink time unit, determining the size of the HARQ-ACK/NACK codebook by combining the maximum value in the second type of DAI of all scheduled downlink time units corresponding to the uplink time unit and the number of HARQ-ACK/NACK bits corresponding to each downlink time unit; and determining the size of the HARQ-ACK/NACK code book based on the bit number indicated by the second type DAI under the condition that the second type DAI indicates the total bit number of the HARQ-ACK/NACK code book.

The number of HARQ-ACK/NACK bits corresponding to each downlink time unit may be predefined by a standard or configured semi-statically, where the number of HARQ-ACK/NACK bits corresponding to each downlink time unit is determined according to one of the following: the number of the most transmittable transmission blocks per downlink time unit, the number of the most transmittable coding blocks per downlink time unit, and the number of the most transmittable coding block groups per downlink time unit.

The control signaling may further include information indicating that the number of HARQ-ACK/NACK bits corresponding to each downlink time unit is determined according to the number of the maximum transmittable transport blocks of each downlink time unit, or according to the number of the maximum transmittable coding block groups of each downlink time unit.

The determination unit may determine the size of the HARQ-ACK/NACK codebook corresponding to the uplink time unit based on the size of the HARQ-ACK/NACK codebook configured by the base station.

The determining unit may obtain a minimum number of bits that the HARQ-ACK/NACK corresponding to each HARQ process may occupy by dividing the determined size of the HARQ-ACK/NACK codebook by a total number of HARQ processes supportable in one uplink time unit; and obtaining the starting point of the HARQ-ACK/NACK corresponding to each downlink time unit corresponding to the uplink time unit in the HARQ-ACK/NACK code book by multiplying the minimum bit number which can be occupied by the HARQ-ACK/NACK corresponding to each HARQ process by the ID of the HARQ process of each downlink time unit corresponding to the uplink time unit.

The generation unit may generate HARQ-ACK/NACK according to the received PDSCH for an effective HARQ process, and insert HARQ-ACK/NACK generated for the effective HARQ process into the HARQ-ACK/NACK codebook based on a starting point of HARQ-ACK/NACK in the HARQ-ACK/NACK codebook corresponding to a downlink time unit corresponding to the effective HARQ process; for an invalid HARQ process, generating HARQ-NACK according to a predefined rule, and inserting the HARQ-NACK generated for the invalid HARQ process into the HARQ-ACK/NACK codebook based on a starting point of the HARQ-ACK/NACK in the HARQ-ACK/NACK codebook corresponding to a downlink time unit corresponding to the invalid HARQ process.

The generation unit may occupy the HARQ-ACK/NACK corresponding to the valid HARQ process at a position of the HARQ-ACK/NACK corresponding to the immediately subsequent HARQ process when the number of bits of the HARQ-ACK/NACK corresponding to the valid HARQ process is greater than the minimum number of bits that the HARQ-ACK/NACK corresponding to each HARQ process can occupy, wherein the inserting the HARQ-NACK generated for the invalid HARQ process into the HARQ-ACK/NACK codebook includes: when the position of the HARQ-ACK/NACK corresponding to the invalid HARQ process is occupied by the HARQ-ACK/NACK corresponding to the valid HARQ process, the bit number of the HARQ-ACK/NACK corresponding to the invalid HARQ process is determined as the difference between the minimum bit number which can be occupied by the HARQ-ACK/NACK corresponding to each HARQ process and the occupied bit number of the HARQ-ACK/NACK corresponding to the valid HARQ process.

The determining unit may calculate downlink time unit indexes of the respective downlink time units corresponding to the uplink time units based on the information on the HARQ-ACK/NACK timings, wherein the downlink time unit indexes of the respective downlink time units corresponding to the uplink time units respectively indicate relative time orders of the respective downlink time units corresponding to the uplink time units in a feedback window; obtaining the minimum bit number which can be occupied by the HARQ-ACK/NACK corresponding to each downlink time unit by dividing the size of the HARQ-ACK/NACK code book by the size of a feedback window; and obtaining the starting point of the HARQ-ACK/NACK corresponding to each downlink time unit corresponding to the uplink time unit in the HARQ-ACK/NACK codebook by multiplying the minimum bit number which can be occupied by the HARQ-ACK/NACK corresponding to each downlink time unit by the downlink time unit index of each downlink time unit corresponding to the uplink time unit.

The determining unit may calculate a size of a feedback window based on information about HARQ-ACK/NACK timing, wherein the feedback window is a set of all downlink time units that may feed back HARQ-ACK/NACK in the uplink time unit at the same time, determined by all possible values of the HARQ-ACK timing; determining downlink time unit indexes of the downlink time units corresponding to the uplink time units based on the information on the HARQ-ACK/NACK timing, wherein the downlink time unit indexes of the downlink time units corresponding to the uplink time units respectively represent relative time sequences of the downlink time units corresponding to the uplink time units in a feedback window; obtaining the minimum bit number which can be occupied by the HARQ-ACK/NACK corresponding to each downlink time unit by dividing the size of the HARQ-ACK/NACK code book by the size of a feedback window; and obtaining the starting point of the HARQ-ACK/NACK corresponding to each downlink time unit corresponding to the uplink time unit in the HARQ-ACK/NACK codebook by multiplying the minimum bit number which can be occupied by the HARQ-ACK/NACK corresponding to each downlink time unit by the downlink time unit index of each downlink time unit corresponding to the uplink time unit.

The generation unit may generate HARQ-ACK/NACK according to the received PDSCH for an effective downlink time unit and insert the HARQ-ACK/NACK generated for the effective downlink time unit into the HARQ-ACK/NACK codebook based on a starting point of the HARQ-ACK/NACK in the HARQ-ACK/NACK codebook corresponding to the effective downlink time unit; generating HARQ-NACK according to a predefined rule for an invalid downlink time unit and inserting the generated HARQ-NACK for the invalid downlink time unit into the HARQ-ACK/NACK codebook based on a starting point of the HARQ-ACK/NACK in the HARQ-ACK/NACK codebook corresponding to the invalid downlink time unit, or generating HARQ-NACK according to a predefined rule for a downlink time unit for which the PDSCH is not received and inserting the generated HARQ-NACK into the HARQ-ACK/NACK codebook based on a position of the HARQ-ACK/NACK in the HARQ-ACK/NACK codebook corresponding to a downlink time unit for which the PDSCH is not received; generating HARQ-ACK/NACK according to the PDSCH aiming at the uplink time unit which receives the PDSCH but corresponds to the HARQ-ACK/NACK of the PDSCH is not the downlink time unit of the uplink time unit, and inserting the generated HARQ-ACK/NACK into the HARQ-ACK/NACK code book.

The generation unit may determine, when the number of bits of the HARQ-ACK/NACK corresponding to the valid downlink time unit is greater than the minimum number of bits that the HARQ-ACK/NACK corresponding to each downlink time unit may occupy, the position of the HARQ-ACK/NACK corresponding to the valid downlink time unit corresponding to the immediately subsequent downlink time unit, and when the position of the HARQ-ACK/NACK corresponding to the invalid downlink time unit is occupied by the HARQ-ACK/NACK corresponding to the valid downlink time unit, the number of bits of the HARQ-ACK/NACK corresponding to the invalid downlink time unit as a difference between the minimum number of bits that the HARQ-ACK/NACK corresponding to each downlink time unit may occupy and the number of bits of the HARQ-ACK/NACK corresponding to the valid downlink time unit.

The determining unit may determine, based on the values of the first class of DAIs of all scheduled downlink time units corresponding to the uplink time unit, positions of HARQ-ACK/NACKs corresponding to respective downlink time units of all scheduled downlink time units corresponding to the uplink time unit in the HARQ-ACK/NACK codebook.

The generation unit may sequentially insert HARQ-ACK/NACK corresponding to all scheduled downlink time units from the starting position of the HARQ-ACK/NACK codebook according to the size of the relative time sequence indicated by the first class DAI of all scheduled downlink time units corresponding to the uplink time unit, and insert a placeholder bit at a subsequent position.

When the HARQ-ACK/NACK code book is generated, if at least two PDSCHs correspond to the same transmission block in the same HARQ-ACK/NACK code book, the user terminal generates HARQ-ACK/NACK bits for the last PDSCH in time sequence according to the decoding result of the PDSCH and sets the HARQ-ACK/NACK bit values of all the coding block groups of the previous PDSCH as a predefined value for the same transmission block when generating the HARQ-ACK/NACK of the PDSCH; or, for the same transport block, the user terminal sets the HARQ-ACK/NACK values of all received PDSCHs to the same value, and the value is generated according to the demodulation result of the last received PDSCH.

When the total bit number of the uplink control signaling at least containing the HARQ-ACK/NACK to be fed back in the uplink time unit exceeds the maximum bit number of the uplink control signaling which can be carried by the PUCCH resource configured by the base station, the sending unit can execute one of the following operations: compressing the bits of the HARQ-ACK/NACK which need to be fed back in the uplink time unit according to a predefined rule; using a next larger PUCCH resource capable of bearing the total bit number of the uplink control signaling to be fed back to send the uplink control signaling in the uplink time unit; receiving downlink scheduling information indicating a new PUCCH resource capable of bearing the total bit number of an uplink control signaling to be fed back from a base station in a current downlink time unit or at least the last downlink time unit corresponding to the uplink time unit, and sending the uplink control signaling in the uplink time unit by using the new PUCCH resource; and giving up sending the HARQ-ACK/NACK of the downlink time unit with low priority, so that the total bit number of the sent uplink control signaling does not exceed the maximum bit number of the uplink control signaling which can be carried by the PUCCH resource configured by the base station.

According to another aspect of the present invention, there is provided a downlink transmission apparatus, including: a configuration unit configured to configure a control signaling; a sending unit, configured to send the PDSCH and control signaling to the user equipment in a downlink time unit, where the control signaling is used to determine at least one of the following for the user equipment to feedback: an uplink time unit of HARQ-ACK/NACK corresponding to PDSCH, the size of HARQ-ACK/NACK code book corresponding to the uplink time unit, and the position of HARQ-ACK/NACK corresponding to each downlink time unit corresponding to the uplink time unit in the HARQ-ACK/NACK code book.

According to the invention, under the condition that the HARQ-ACK feedback time is variable, the user equipment can accurately judge the size and bit mapping of the HARQ-ACK code book, and meanwhile, the effective utilization of the uplink control channel resources is ensured.

Drawings

These and/or other aspects and advantages of the present invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a flowchart of a method of transmitting HARQ-ACK/NACK according to the present invention;

fig. 2 is a diagram of a HARQ process (HARQ process) according to a first exemplary embodiment of the present invention;

fig. 3 is a diagram of uplink and downlink mapping based on HARQ processes according to a first exemplary embodiment of the present invention;

fig. 4 is a diagram for generating HARQ-ACK/NACK based on a HARQ process according to a first exemplary embodiment of the present invention;

fig. 5 is another diagram for generating HARQ-ACK/NACK based on a HARQ process according to the first exemplary embodiment of the present invention;

fig. 6 is a diagram of uplink and downlink mapping based on downlink time units according to a first exemplary embodiment of the present invention;

fig. 7 is a diagram for generating HARQ-ACK/NACK based on a downlink time unit according to the first exemplary embodiment of the present invention;

fig. 8 is a diagram of uplink and downlink mapping based on downlink time units according to a second exemplary embodiment of the present invention;

fig. 9 is another diagram of uplink and downlink mapping based on downlink time units according to a second exemplary embodiment of the present invention;

fig. 10 is a schematic diagram of uplink and downlink mapping based on downlink time units according to a third exemplary embodiment of the present invention;

fig. 11 is another diagram of uplink and downlink mapping based on downlink time units according to a third exemplary embodiment of the present invention;

fig. 12 is another diagram of uplink and downlink mapping based on downlink time units according to a third exemplary embodiment of the present invention;

fig. 13 is another diagram of uplink and downlink mapping based on downlink time units according to a third exemplary embodiment of the present invention;

fig. 14 is a flowchart of a downlink transmission method according to the present invention;

fig. 15 is a block diagram of an apparatus for transmitting HARQ-ACK/NACK according to the present invention;

fig. 16 is a block diagram of a downstream transmission apparatus according to the present invention;

fig. 17 is a diagram of uplink and downlink mapping based on downlink time units according to a third exemplary embodiment of the present invention;

fig. 18 is another diagram of uplink and downlink mapping based on downlink time units according to the third exemplary embodiment of the present invention.

Detailed Description

The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of embodiments of the invention defined by the claims and their equivalents. Various specific details are included to aid understanding, but these are to be considered exemplary only. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.

Fig. 1 is a flowchart of a method of transmitting HARQ-ACK/NACK according to the present invention. A method of transmitting HARQ-ACK/NACK by a user equipment according to an exemplary embodiment of the present invention will be described with reference to fig. 1.

First, in step 101, a user equipment receives a PDSCH and control signaling from a base station in a downlink time unit.

Here, the control signaling is downlink scheduling signaling carried through a PDCCH or control signaling carried through a PDSCH. The control signaling may include information about HARQ-ACK/NACK timing.

According to an exemplary embodiment, the information on the HARQ-ACK/NACK timing may be indicated by dynamic signaling or semi-static signaling. For example, the indication may be performed by downlink control signaling DCI carried by a PDCCH, or may be performed by higher layer control signaling carried by a PDSCH, or may be performed by a combination of the two.

According to an exemplary embodiment, the number of bits of the information on the HARQ-ACK/NACK timing may be predefined by a standard or semi-statically configured by the base station. For example, the standard predefines the number of bits of information about HARQ-ACK/NACK timing as 2 bits, or the higher layer signaling configures the time difference k of ACK/NACK feedback to PDSCH reception _i I =0,1,2. Indicating HARQ-ACK/NACK timing value with 2 bits in DCI, one of four time differences i =0,1,2,3 may be indicated. The base station may configure different k for different service types or different DCIs _i Values or configuration of different numbers of bits. For example, the number of bits of the information of the HARQ-ACK/NACK timing of DCI in the common search region of the downlink control channel PDCCH is 0 bit, the HARQ-ACK/NACK timing value is a fixed value predefined by a standard, and the number of bits of the information of the HARQ-ACK/NACK timing of DCI in the user-specific search region of the downlink control channel PDCCH is 2 bit, the HARQ-ACK/NACK timing value is a set of values configured in a higher layer or predefined by a standard, or the number of bits of the information of the HARQ-ACK/NACK timing defining a certain DCI or a class of DCI is 0 bit, the HARQ-ACK/NACK timing value is predefined by a standard, and the number of bits of the information of the HARQ-ACK/NACK timing of other DCI type is 2, the HARQ-ACK/NACK timing value is a set of values configured in a higher layer or predefined by a standard.

According to an exemplary embodiment, the information on the HARQ-ACK/NACK timing may indicate a time difference from a downlink time unit where the PDSCH is located to an uplink time unit where the HARQ-ACK/NACK is fed back. For example, the downlink time unit where the PDSCH is located is n, the corresponding uplink time unit m where HARQ-ACK/NACK is fed back, and the information on HARQ-ACK/NACK timing may indicate m-n.

According to the exemplary embodiment, the time difference from the downlink time unit where the PDSCH is located to the uplink time unit where the HARQ-ACK/NACK is fed back is the information about the timing of the HARQ-ACK/NACK and the time difference offset k ₀ The sum of the additions. For example, if the information about the HARQ-ACK/NACK timing is 2 bits, the downlink time unit where the PDSCH is located is n, and the corresponding uplink time unit m where the HARQ-ACK/NACK is fed back, the time difference m-n from the downlink time unit where the PDSCH is located to the uplink time unit where the HARQ-ACK/NACK is fed back may be k ₀ +0，k ₀ +1，…,k ₀ +3。

Here, the time difference offset k is either standard predefined or higher layer configured. Different HARQ-ACK/NACK timing values, and/or k, may be predefined according to different traffic types, or different DCIs ₀ Are different values. Preferably, different DCIs, predefined different HARQ-ACK/NACK timing values and/or k ₀ The timing value of HARQ-ACK/NACK of DCI in a common search region of a downlink control channel PDCCH can be different values and/or k ₀ HARQ-ACK/NACK timing values and/or k for DCI within a user-specific search region of a downlink control channel PDCCH for one or a set of values predefined by a criterion ₀ One or a group of values configured for higher layers, or one or a class of DCI, HARQ-ACK/NACK timing values and/or k ₀ One or a set of values predefined for the standard, and other types of DCI, HARQ-ACK/NACK timing values and/or k ₀ One or a set of values configured for higher layers. Alternatively, the criteria may predefine multiple sets of HARQ-ACK/NACK timing values and/or k ₀ Values, e.g., sets of values predefined for UEs of different processing capabilities, and the base station semi-statically indicates which set of HARQ-ACK/NACK timing values to employ. For TDD systems, standard predefined HARQ-ACK/NACK timing may be assumed for uplink time unit m corresponding to ACK/NACK of downlink time unit n determined according to TDD configuration ₀ Or the next or next few available uplink time units m _i (i>0) One of them. Since the uplink time unit of the TDD system is often discrete, if the absolute time difference between the uplink time unit fed back by ACK/NACK and the downlink reception is directly indicated by DCI, it is requiredThe bit overhead is large. Therefore, the uplink unit fed back by ACK/NACK can be determined by combining the uplink and downlink information of TDD. The uplink time unit m determined according to the uplink and downlink information of TDD ₀ ～m _i The determination may be performed according to the semi-statically configured TDD uplink/downlink ratio, or according to the received uplink/downlink ratio information indicated by the dynamic signaling. For example, the ue receives the uplink and downlink timeslot indication in the downlink time unit n as DSUDDDSUDD for 10 time units starting from the current time unit n, and receives the uplink and downlink timeslot indication in the downlink time unit n +8 as DSUUU for 5 time units starting from the current time unit n + 8. Then, assuming that 2 bits still indicate the ACK/NACK feedback time, if the UE receives DCI in the downlink time unit n, the 2 bits respectively indicate the uplink time units n +7, n +10, n +11 and n +12. Where n +7 is the first uplink time unit satisfying the minimum time delay for ACK/NACK feedback, and n +10, n +11, and n +12 are the nearest 2,3,4 available uplink time units, respectively.

According to an exemplary embodiment, the higher layer signaling configures the uplink time unit in which PUCCH can be transmitted. For example, a cycle and a time offset are configured to determine an uplink time unit in which the PUCCH can be transmitted. In this case, the information on the HARQ-ACK/NACK timing indicates that one or more of the configured PUCCH uplink time units are greater than or equal to the minimum time difference from the downlink time unit where the PDSCH is located to the uplink time unit where the HARQ-ACK/NACK is fed back and is closest to the minimum time difference. Here, the minimum time difference may be a fixed value, or may be different values for different service types, or different values for different UE processing capabilities. For example, when the period of the uplink time unit is N1, the uplink time unit N satisfies N mod N1=0, and when the information on the HARQ-ACK/NACK timing is 2 bits, it indicates the 1 st, 2 nd, 3 rd, and 4 th uplink time units configured according to the period, which are greater than or equal to the minimum time difference from the downlink time unit in which the PDSCH is located to the uplink time unit in which the HARQ-ACK/NACK is fed back and which are closest to the minimum time difference.

According to an exemplary embodiment, in case that the base station semi-statically configures an uplink time unit in which the PUCCH can be transmitted, the information on the HARQ-ACK/NACK timing further indicates whether a time difference from a downlink time unit in which the predefined PDSCH is located to an uplink time unit in which the HARQ-ACK/NACK is fed back or one or more of the PUCCH-configured uplink time units that are greater than or equal to the time difference from the downlink time unit in which the predefined PDSCH is located to the uplink time unit in which the HARQ-ACK/NACK is fed back and are closest to the time difference. For example, the predefined HARQ-ACK/NACK timing for PDSCH and ACK/NACK feedback is 3 time units, e.g., PDSCH is received in downlink time unit n, and ACK/NACK is fed back in uplink time unit n + 3. The semi-statically configured uplink time unit satisfies N mod N1=0, where N1 represents a period of the semi-statically configured uplink time unit. Then, 1 bit in the DCI scheduling the PDSCH of the downlink time unit N may indicate whether ACK/NACK is fed back in the uplink time unit N +3 or ACK/NACK is fed back in the uplink time unit N + N, where N > =3, and (N + N) mod N1=0. The ACK/NACK codebook transmitted in the semi-statically configured uplink time unit may determine the ACK/NACK codebook size according to N1 downlink time units, and the ACK/NACK codebook transmitted in the non-semi-statically configured uplink time unit determines the codebook size according to one downlink time unit.

Preferably, the control signaling may further include indication information of a HARQ-ACK/NACK codebook size.

According to an exemplary embodiment, the base station configures a codebook size of HARQ-ACK/NACK.

According to an exemplary embodiment, the base station configures the total number of HARQ processes, or is predefined by a standard. And, the base station configures the number of HARQ-ACK/NACK bits for each HARQ process, or is predefined by a standard. The size of the HARQ-ACK/NACK code book is determined according to the total number of HARQ processes and the number of HARQ-ACK/NACK of each HARQ process.

According to an exemplary embodiment, the base station configures the HARQ-ACK/NACK feedback window, or the HARQ-ACK/NACK feedback window is predefined by a standard. Here, the HARQ-ACK/NACK feedback window is a set of all downlink time units that may simultaneously feed back HARQ-ACK/NACK in the uplink time unit, determined by all possible values of the HARQ-ACK timing. And the base station semi-statically configures the HARQ-ACK/NACK bit number of each downlink time unit in the HARQ-ACK/NACK feedback window, or the HARQ-ACK/NACK bit number of each downlink time unit is predefined by a standard. Therefore, the size of the HARQ-ACK/NACK codebook is determined according to the size of the HARQ-ACK/NACK feedback window and the number of HARQ-ACK/NACK of each downlink time unit in the feedback window. Here, the number of HARQ-ACK/NACK bits corresponding to each downlink time unit may be determined according to one of the following: the number of the most transmittable transmission blocks per downlink time unit, the number of the most transmittable coding blocks per downlink time unit, and the number of the most transmittable coding block groups per downlink time unit. Here, the control signaling may include information indicating that the number of HARQ-ACK/NACK bits corresponding to each downlink time unit is determined according to the number of transport blocks that can be transmitted at most per downlink time unit, or according to the number of coding block groups that can be transmitted at most per downlink time unit.

Preferably, when the number of HARQ-ACK/NACK bits corresponding to each downlink time unit is configured according to the maximum number of coding block groups that can be transmitted in each downlink time unit, the HARQ-ACK/NACK bits are determined according to the number of coding block groups regardless of whether scheduling signaling based on a transport block or scheduling signaling based on a coding block group is used for scheduling the downlink time unit.

Preferably, the control signaling may further include a first type of DAI, where the first type of DAI indicates one of the following information: relative time sequence of the current scheduled downlink time unit in all the scheduled downlink time units corresponding to the uplink time unit, and bit position of HARQ-ACK/NACK bit of the current scheduled downlink time unit in HARQ-ACK/NACK code book. The user equipment can also determine the size of the HARQ-ACK/NACK code book corresponding to each uplink time unit and the position of the HARQ-ACK/NACK corresponding to each downlink time unit corresponding to each uplink time unit in the HARQ-ACK/NACK code book according to the first type of DAI. Here, the HARQ-ACK/NACK codebook size corresponding to each uplink time unit determined by the first-type DAI is variable, so that it can be guaranteed that resources of the uplink control channel are effectively utilized.

According to a preferred embodiment of the present invention, in the control signaling, the first type of DAI may be jointly encoded with information on HARQ-ACK/NACK timing. In this way, the bits of the downlink control signaling can be compressed, thereby ensuring that the resources of the downlink control channel are effectively utilized.

Preferably, the control signaling may further include a second type DAI. Here, the DAI of the second type indicates one of the following information: the total number of downlink time units of all scheduled downlink time units corresponding to the uplink time unit, the total number of downlink time units from a first downlink time unit to a current downlink time unit in all scheduled downlink time units corresponding to the uplink time unit, and the total bit number of the second-class DAI indication HARQ-ACK/NACK codebook. The user equipment may determine HARQ-ACK/NACK codebook sizes corresponding to respective uplink time units using the second type DAI. Here, the HARQ-ACK/NACK codebook size corresponding to each uplink time unit determined by the second type DAI is variable, so that it can be guaranteed that resources of the uplink control channel are effectively utilized.

According to a preferred embodiment of the present invention, the first type DAI, the second type DAI, and information on HARQ-ACK/NACK timing may be jointly encoded in the control signaling. In this way, the bits of the downlink control signaling can be compressed, thereby ensuring that the resources of the downlink control channel are effectively utilized.

Preferably, the control signaling may include a third type of DAI, where the content of the third type of DAI indication is the same as the content of the second type of DAI indication, or the third type of DAI indicates the total number of bits of the HARQ-ACK/NACK codebook expected to be received by the base station, and the total number of bits of the HARQ-ACK/NACK corresponding to the PDSCH actually scheduled by the base station is less than or equal to the expected total number of bits. The control signaling including the first type of DAI and/or the second type of DAI and the control signaling including the third type of DAI may be independent signaling, for example, one is DCI for scheduling downlink transmission, and the other is DCI for scheduling uplink transmission.

Hereinafter, the above-described preferred embodiments will be described in detail in connection with exemplary embodiments of the present invention. Referring back to fig. 1, then, in step 102, the user equipment determines, based on the control signaling, an uplink time unit for feeding back HARQ-ACK/NACK corresponding to the received PDSCH, a size of a HARQ-ACK/NACK codebook corresponding to the uplink time unit, and a position of HARQ-ACK/NACK corresponding to each downlink time unit corresponding to the uplink time unit in the HARQ-ACK/NACK codebook. Subsequently, a specific embodiment of this step will be described in detail with reference to fig. 2 to 13.

Next, in step 103, an HARQ-ACK/NACK codebook is generated based on the size of the HARQ-ACK/NACK codebook and the position of the HARQ-ACK/NACK corresponding to each downlink time unit corresponding to the uplink time unit in the HARQ-ACK/NACK codebook. Subsequently, a specific embodiment of this step will be described in detail with reference to fig. 2 to 13.

Finally, in step 104, the HARQ-ACK/NACK codebook generated in step S107 is transmitted in uplink time units.

The first exemplary embodiment according to the present invention will be described below。

In the first exemplary embodiment, the control signaling received by the user equipment from the base station may further include the size of the HARQ-ACK/NACK codebook configured by the base station.

Accordingly, the user equipment may determine the size of the HARQ-ACK/NACK codebook corresponding to the uplink time unit based on the size of the HARQ-ACK/NACK codebook configured by the base station in step 103.

According to an aspect of the first exemplary embodiment, the control signaling further includes a total number of HARQ processes supportable in one uplink time unit and a HARQ process ID, or the control signaling further includes a HARQ process ID, and the total number of HARQ processes supportable in one uplink time unit is standard predefined. Accordingly, the user equipment may generate a HARQ-ACK/NACK codebook corresponding to an uplink time unit based on a HARQ process (HARQ process).

Referring to fig. 2, fig. 2 is a schematic diagram of a HARQ process according to a first exemplary embodiment of the present invention. In the example of fig. 2, it is assumed that the total number of supportable HARQ processes in one uplink time unit is 8. Here, the total number of HARQ processes supportable in one uplink time unit may be included in the control signaling or may be standard predefined. HARQ-ACK/NACK corresponding to each HARQ process that receives PDSCH in the downlink time unit may be mapped to the HARQ-ACK/NACK codebook of the uplink time unit, as shown in fig. 3.

Accordingly, in step 102, the user equipment may determine the position of HARQ-ACK/NACK corresponding to each downlink time unit corresponding to an uplink time unit in the HARQ-ACK/NACK codebook based on the size of the HARQ-ACK/NACK codebook, the total number of HARQ processes supportable in one uplink time unit, and the ID of each HARQ process.

Specifically, the minimum number of bits Y that the HARQ-ACK/NACK corresponding to each HARQ process can occupy, i.e., Y = (X/L), is obtained by dividing the determined size X of the HARQ-ACK/NACK codebook by the total number L of the HARQ processes supportable in one uplink time unit.

And then multiplying the minimum bit number which can be occupied by the HARQ-ACK/NACK corresponding to each HARQ process by the ID i of the HARQ process of each downlink time unit corresponding to the uplink time unit, for example, i =0,1, \8230; L-1, so as to obtain the starting point Y i, i =0,1, \8230; L-1 of the HARQ-ACK/NACK corresponding to each downlink time unit corresponding to the uplink time unit in the HARQ-ACK/NACK codebook.

In step 103, the user equipment may generate HARQ-ACK/NACK based on the HARQ process. Here, the HARQ process may be divided into an active HARQ process and an inactive HARQ process. The valid HARQ process refers to a HARQ process which receives the PDSCH in a downlink time unit corresponding to an uplink time unit, the time difference between the uplink time unit and the downlink time unit where the PDSCH is located is larger than or equal to a predefined minimum time delay, the invalid HARQ process refers to a HARQ process which does not receive the PDSCH in the downlink time unit corresponding to the uplink time unit, and/or receives the PDSCH in the downlink time unit, but the time difference between the uplink time unit and the downlink time unit where the PDSCH is located is smaller than the predefined minimum time delay, and/or receives the PDSCH in the downlink time unit, but the HARQ-ACK/NACK of the PDSCH is fed back before the uplink time unit.

Preferably, the effective HARQ process refers to a HARQ process feeding back HARQ-ACK/NACK in the uplink time unit, that is, the UE receives the PDSCH in the downlink time unit, and the HARQ-ACK/NACK of the PDSCH is fed back in the uplink time unit. If the UE receives the PDSCH in a downlink time unit but the HARQ-ACK/NACK feedback for the PDSCH is not in the uplink time unit, then this HARQ process is an invalid HARQ process for the uplink time unit.

And for the effective HARQ process, the user equipment generates HARQ-ACK/NACK according to the received PDSCH, and inserts the HARQ-ACK/NACK generated for the effective HARQ process into the HARQ-ACK/NACK codebook based on the starting point of the HARQ-ACK/NACK corresponding to the downlink time unit corresponding to the effective HARQ process in the HARQ-ACK/NACK codebook.

For an invalid HARQ process, the user equipment generates HARQ-NACK according to a predefined rule, and inserts the HARQ-NACK generated for the invalid HARQ process into an HARQ-ACK/NACK codebook based on the starting point of the HARQ-ACK/NACK corresponding to the downlink time unit corresponding to the invalid HARQ process in the HARQ-ACK/NACK codebook.

And when the bit number of the HARQ-ACK/NACK corresponding to the effective HARQ process is larger than the minimum bit number which can be occupied by the HARQ-ACK/NACK corresponding to each HARQ process, the user equipment enables the HARQ-ACK/NACK corresponding to the effective HARQ process to occupy the position of the HARQ-ACK/NACK corresponding to the immediately following HARQ process. For example, specifically, the number Z of ACK/NACK bits of HARQ processes (i.e., effective HARQ processes) that receive the PDSCH in the corresponding time unit may be equal to or greater than Y. At this time, the ACK/NACK bits corresponding to the HARQ process may occupy the ACK/NACK bit number of the immediately following HARQ process.

When the position of the HARQ-ACK/NACK corresponding to the invalid HARQ process is occupied by the HARQ-ACK/NACK corresponding to the valid HARQ process, the user equipment determines the number of bits of the HARQ-ACK/NACK corresponding to the invalid HARQ process as the difference between the number of bits that the HARQ-ACK/NACK corresponding to each HARQ process can occupy and the number of bits that the HARQ-ACK/NACK corresponding to the valid HARQ process occupies. For example, the number of ACK/NACK bits Z' of the HARQ process that does not receive the PDSCH in the corresponding time unit (i.e., the invalid HARQ process) is determined according to whether it is occupied by ACK/NACK of the valid HARQ process. Z' = Y if not occupied by ACK/NACK for active HARQ processes. If occupied by ACK/NACK for a valid HARQ process, assuming the number of occupied bits is Y1, then Z' = Y-Y1. When Y = Y1, Z' =0.

Therefore, according to the embodiment of the present invention, in order to avoid overlapping of ACK/NACK bits of effective HARQ processes, the base station should avoid scheduling adjacent HARQ processes feeding back ACK/NACK on the same uplink time unit when performing scheduling.

Fig. 4 is a diagram for generating HARQ-ACK/NACK based on a HARQ process according to a first exemplary embodiment of the present invention.

Assuming that X =16, l =8, y =2, z =4, the ACK/NACK codebook length is 16. If the HARQ process 2 receives the PDSCH in the corresponding time unit, 4-bit ACK/NACK is generated according to the decoding result of the PDSCH, and if other HARQ processes do not receive the PDSCH in the corresponding time units, the 0 th bit to the 3 rd bit in the ACK/NACK code book respectively correspond to the HARQ process 0 and the HARQ process 1. Due to non-scheduling, Y =2 bit NACKs are generated respectively, the 4 th bit to the 7 th bit correspond to

HARQ process

2, and 4 bit ACK/NACK is generated according to a PDSCH decoding result. The 8 th bit to the 15 th bit correspond to HARQ processes 4 to 7, respectively, and Y =2 bit NACK is generated due to non-scheduling, respectively. It is readily apparent that 4 bits of HARQ process 2 occupy 2 bit positions of HARQ process 3.

In this example, the base station should avoid scheduling HARQ process 3 if the base station needs to schedule other HARQ processes as well. This is because the ACK/NACK bit for HARQ process 3 is already occupied by HARQ process 2. In which case the base station may schedule, for example, HARQ process 4.

Fig. 5 is another diagram for generating HARQ-ACK/NACK based on a HARQ process according to the first exemplary embodiment of the present invention.

Referring to fig. 5, assuming that X =16, l =8, y =2, z =4, the ACK/NACK codebook length is 16. If the HARQ process 2 and the HARQ process 4 receive the PDSCH in the corresponding time unit, 4-bit ACK/NACK is generated according to the decoding result of the PDSCH, and if other HARQ processes do not receive the PDSCH in the corresponding time unit, the 0 th bit to the 3 rd bit in the ACK/NACK code book respectively correspond to the HARQ process 0 and the HARQ process 1. Due to non-scheduling, Y = 2-bit NACKs are generated, respectively. The 4 th bit to the 7 th bit correspond to the HARQ process 2, and generate 4-bit ACK/NACK according to the PDSCH decoding result. The 8 th bit to the 11 th bit correspond to the HARQ process 4, and generate 4-bit ACK/NACK according to the PDSCH decoding result. The 12 th bit to the 15 th bit correspond to HARQ processes 6 to 7, respectively, and Y =2 bit NACK is generated due to non-scheduling, respectively. It is readily seen that 4 bits of HARQ process 2 occupy 2 bit positions of

HARQ process

3 and 4 bits of HARQ process 4 occupy 2 bit positions of HARQ process 5.

In this example, the base station should avoid scheduling HARQ process 3 and HARQ process 5 if the base station needs to schedule other HARQ processes. This is because the ACK/NACK bit of HARQ process 3 has been occupied by HARQ process 2 and the ACK/NACK bit of HARQ process 5 has been occupied by HARQ process 4. In which case the base station may schedule, for example, HARQ process 6.

It should be noted that, although in the above example, the HARQ IDs and the time sequence of the downlink time unit are in one-to-one correspondence, the present invention is also applicable to the case where the HARQ ID size and the time sequence of the downlink time unit are not in one-to-one correspondence. For example, downlink time unit n is an HARQ process with HARQ ID =6, and downlink time unit n +4 is an HARQ process with HARQ ID =1. Then, when mapping the HARQ-ACK bits, the HARQ-ACK bits are still in the order of HARQ ID, i.e., HARQ-ACK bits for HARQ ID =1 precede HARQ-ACK bits for HARQ ID = 6.

According to another aspect of the first exemplary embodiment, the user equipment may generate the HARQ-ACK/NACK codebook corresponding to the uplink time unit based on the downlink time unit. Therefore, the user equipment can also determine the position of the HARQ-ACK/NACK corresponding to the PDSCH of each time unit in the HARQ-ACK/NACK code book based on the downlink time unit index.

Specifically, first, the user equipment determines the size of a feedback window and a downlink time unit index of each downlink time unit corresponding to the uplink time unit based on information on HARQ-ACK/NACK timing. Here, the feedback window is a set of all downlink time units that may simultaneously feed back HARQ-ACK/NACK in the uplink time unit, which is determined by all possible values of the HARQ-ACK timing, and downlink time unit indexes of the downlink time units corresponding to the uplink time unit respectively indicate relative time sequences of the downlink time units corresponding to the uplink time unit in the feedback window.

For example, fig. 6 is a schematic diagram of uplink and downlink mapping based on downlink time units according to the first exemplary embodiment of the present invention.

Referring to fig. 6, assuming that the size of the feedback window is L, an earliest time unit in time within the feedback window corresponds to the smallest time unit index, e.g., 0, and a latest time unit in time within the feedback window corresponds to the largest time unit index, e.g., L-1. The time units within the feedback window may or may not be contiguous. For example, if the number of bits indicating HARQ-ACK/NACK timing in downlink control signaling (DCI) is N, 2^ N time values can be indicated, i.e., HARQ-ACK/NACK of PDSCH of 2^ N downlink time units can be fed back at most in the same uplink time unit. Then the size of the feedback window L =2 n. The HARQ-ACK/NACK timing values indicated in the DCI may be predefined according to a standard. For example, 3 bits may indicate that the difference m-n from time unit n of PDSCH to time unit m of corresponding HARQ-ACK/NACK is 0,1, \8230; 7, then the size of the feedback window L =8, and the time units within the feedback window are consecutive.

For another example, if 2 bits indicate HARQ-ACK/NACK timing in DCI, the size of the feedback window L =4, and if the value of HARQ-ACK/NACK timing (i.e., the time relationship of PDSCH and HARQ-ACK/NACK) indicated in the higher-layer configuration DCI is 0,2,4,6, the feedback window is composed of 4 time units with an interval of 2.

For another example, the partial time unit in the feedback window may be a time unit in which the downlink PDSCH is not transmitted, for example, in a TDD system, if the time unit is configured as an uplink time unit, the time unit must not transmit the downlink PDSCH. Then the time unit may be removed when calculating the size L of the feedback window. Preferably, the time unit for affirmatively not sending the PDSCH may be determined through semi-static signaling (such as RRC signaling) or through dynamic signaling (such as DCI indication). Preferably, in calculating the size L of the feedback window, the time element of the PDSCH may be removed regardless of what signaling indicates that the time element is not transmitted with certainty. According to another aspect of the present invention, in calculating the size L of the feedback window, if it is a time unit in which the PDSCH is not transmitted in the affirmative indicated by the semi-static signaling, the time unit may be removed, and if it is a time unit in which the PDSCH is not transmitted in the affirmative indicated by the dynamic signaling, the time unit may not be removed.

Next, the minimum bit number that the HARQ-ACK/NACK corresponding to each downlink time unit can occupy is obtained by dividing the size of the HARQ-ACK/NACK codebook by the size of the feedback window. For example, the minimum bit number Y = X/L that the HARQ-ACK/NACK corresponding to each downlink time unit can occupy can be determined according to the ACK/NACK codebook size X configured by the base station and the size L of the feedback window. Alternatively, the base station configures the bit number of HARQ-ACK/NACK corresponding to each downlink time unit, for example, as described above, the configured bit number is the maximum number of transmittable coding block groups. If the base station configures the UE to dynamically switch between the coding block group based scheduling and the transport block group based scheduling, the number of bits of HARQ-ACK of the UE is always determined according to the coding block group based scheduling, i.e. the maximum number of transmittable coding block groups. Then, the starting point of the HARQ-ACK/NACK corresponding to each downlink time unit corresponding to the uplink time unit in the HARQ-ACK/NACK code book is obtained by multiplying the minimum bit number which can be occupied by the HARQ-ACK/NACK corresponding to each downlink time unit by the downlink time unit index of each downlink time unit corresponding to the uplink time unit. That is, the starting point of HARQ-ACK/NACK corresponding to the downlink time element i is Y × i, i =0,1, … L-1.

After the starting point of the HARQ-ACK/NACK is determined in the above-described manner, the ACK/NACK may be inserted into the HARQ-ACK/NACK codebook for the valid downlink time unit and the invalid downlink time unit. Here, the valid downlink time element means that the PDSCH is received and the uplink time element of the HARQ-ACK/NACK corresponding to the PDSCH is the downlink time element of the uplink time element. The invalid downlink time element is a downlink time element in which the PDSCH is not received or an uplink time element in which the PDSCH is received but HARQ-ACK/NACK corresponding to the PDSCH is not the uplink time element. That is, in the downlink time unit, although the PDSCH is received, since the ACK/NACK feedback time unit is not the ACK/NACK feedback time unit, the downlink time is considered to be an invalid downlink time unit with respect to the ACK/NACK feedback time unit.

Generating HARQ-ACK/NACK according to the received PDSCH for the effective downlink time unit, and inserting the HARQ-ACK/NACK generated for the effective downlink time unit into the HARQ-ACK/NACK codebook based on a starting point of the HARQ-ACK/NACK corresponding to the effective downlink time unit in the HARQ-ACK/NACK codebook.

For an invalid downlink time unit, generating HARQ-NACK according to a predefined rule, and inserting the generated HARQ-NACK for the invalid downlink time unit into the HARQ-ACK/NACK codebook for occupancy based on a starting point of the HARQ-ACK/NACK in the HARQ-ACK/NACK codebook corresponding to the invalid downlink time unit.

Preferably, for a downlink time unit in which the PDSCH is not received among the invalid downlink time units, HARQ-NACK is generated according to a predefined rule, and the generated HARQ-NACK is inserted into the HARQ-ACK/NACK codebook for occupancy based on a position of the HARQ-ACK/NACK in the HARQ-ACK/NACK codebook corresponding to the downlink time unit in which the PDSCH is not received. However, for an uplink time element, which receives the PDSCH but corresponds to the PDSCH, among the invalid downlink time elements, is not a downlink time element of the uplink time element, HARQ-ACK/NACK is generated from the PDSCH, and the generated HARQ-ACK/NACK is inserted into the HARQ-ACK/NACK codebook.

And when the bit number of the HARQ-ACK/NACK corresponding to the effective downlink time unit is larger than the minimum bit number which can be occupied by the HARQ-ACK/NACK corresponding to each downlink time unit, the HARQ-ACK/NACK corresponding to the effective downlink time unit occupies the position of the HARQ-ACK/NACK corresponding to the immediately following downlink time unit. And when the position of the HARQ-ACK/NACK corresponding to the invalid downlink time unit is occupied by the HARQ-ACK/NACK corresponding to the valid downlink time unit, determining the bit number of the HARQ-ACK/NACK corresponding to the invalid downlink time unit as the difference between the bit number capable of being occupied by the HARQ-ACK/NACK corresponding to each downlink time unit and the bit number occupied by the HARQ-ACK/NACK corresponding to the valid downlink time unit. That is, the number Z' of HARQ-ACK/NACK bits for which the PDSCH is not received in the corresponding downlink time unit (referred to as an invalid downlink time unit) is determined according to whether it is occupied by ACK/NACK of the valid downlink time unit. Z' = Y if not occupied by HARQ-ACK/NACK for a valid downlink time unit. If occupied by HARQ-ACK/NACK for an active downlink time unit, assuming the number of occupied bits is Y1, then Z' = Y-Y1. When Y1= Y, Z' =0.

Therefore, in order to avoid the overlapping of the HARQ-ACK/NACK bits of the PDSCH of the active time element, the number L' of downlink time elements for scheduling the HARQ-ACK/NACK fed back in the same uplink time element must be equal to or less than X/Z when the base station schedules. For example, when X =16, L =8, Z =4, the size of the feedback time window determined by the HARQ-ACK/NACK timing is L =8, but the base station can schedule the number of downlink time units L' <4 (X/Z) for which HARQ-ACK/NACK is fed back in the same uplink time unit within the feedback window.

Further, in order to avoid overlapping of HARQ-ACK/NACK bits of the PDSCH of the active time unit, the base station should avoid scheduling the PDSCH of the adjacent time unit that feeds back HARQ-ACK/NACK in the same uplink time unit.

Fig. 7 is a diagram for generating HARQ-ACK/NACK based on a downlink time unit according to the first exemplary embodiment of the present invention.

Referring to fig. 7, assuming that X =16, l =8, y =2, z =4, the HARQ-ACK/NACK codebook length is 16. Assuming that HARQ-ACK/NACK is to be fed back in the uplink time unit m, the feedback window comprises the downlink time unit m-11, m-10, \ 8230;, m-4 and the length is 8. The time unit index of the downlink time unit m-11 is 0, and so on, the time unit index of the downlink time unit m-4 is 7. If the user equipment receives the PDSCH in the time unit index 2, generating 4-bit HARQ-ACK/NACK according to the decoding result of the PDSCH, and not receiving the PDSCH in other time units, wherein the 0 th bit to the 3 rd bit in the HARQ-ACK/NACK codebook respectively correspond to the time unit index 0 and the index 1, and Y = 2-bit HARQ-NACK is generated respectively due to non-scheduling; bits 4 to 7 correspond to the time element index 2, and generate 4 bits HARQ-ACK/NACK according to the PDSCH decoding result. It is easy to see that 4 bits of time index unit 2 occupy 2 bit positions of time index unit 3. Bits 8-15 correspond to downlink time unit indices 4-7, respectively, and since

downlink time units

4,5,7 are not scheduled, although downlink time unit 6 is scheduled, its corresponding HARQ-ACK/NACK is fed back in uplink time unit m +1, and is also an invalid time unit with respect to uplink time unit m. Therefore, the 8 th to 15 th bits are all HARQ-NACKs. Similarly, for the uplink time unit m +1, the downlink time unit included in the feedback window is m-10, m-9, \ 8230;, m-3, and the length is 8. Within the feedback window, only the downlink time unit m-5 (time unit index of 5) schedules the PDSCH and feeds back HARQ-ACK/NACK in the uplink time unit m +1, the HARQ-ACK/NACK codebook size is 16, and among them, bits 12 to 15 generate HARQ-ACK/NACK according to the received PDSCH, and bits 0 to 11 all generate HARQ-NACK.

According to the first exemplary embodiment of the present invention, the feedback overhead of ACK/NACK can be effectively controlled while avoiding the uncertainty of the HARQ-ACK/NACK codebook by configuring the HARQ-ACK/NACK codebook size by the base station. And the base station determines the size of a better HARQ-ACK/NACK code book according to the scheduling flexibility and the feedback overhead. It is easy to see that, in the scheme, even if the UE fails to detect the scheduled PDSCH, the HARQ-ACK/NACK feedback codebook size or the HARQ-ACK/NACK bit ordering is not determined. Because the ACK/NACK feedback codebook size is configured by the higher layer, the starting point of the HARQ-ACK/NACK bit for each HARQ process or downlink time unit is also fixed.

A second exemplary embodiment according to the present invention will be described below.

In the second exemplary embodiment of the present invention, in step 102, the ue determines the size of the HARQ-ACK/NACK codebook according to the size of the feedback window corresponding to the HARQ-ACK/NACK in the uplink time unit. Here, the set of all downlink time units that may feed back HARQ-ACK/NACK in the uplink time unit at the same time, which is determined by all possible values of HARQ-ACK/NACK timing, is referred to as a feedback window.

Specifically, the user equipment may determine the size of the feedback window according to the possible number of values of the information about the HARQ-ACK/NACK timing. For example, the size of the feedback window corresponding to the uplink time unit is obtained by calculating the power N of 2 by the number N of bits of information on HARQ-ACK/NACK timing indicated in DCI; and obtaining the size of the HARQ-ACK/NACK code book corresponding to the uplink time unit by combining the size of the feedback window corresponding to the uplink time unit and the number of HARQ-ACK/NACK bits corresponding to each downlink time unit. Here, the number of HARQ-ACK/NACK bits corresponding to each downlink time unit is predefined by a standard or configured by a higher layer.

Preferably, the number of HARQ-ACK/NACK bits corresponding to each downlink time unit may be determined according to the maximum number of transport blocks, TBs, that can be transmitted in each downlink time unit.

Preferably, the number of HARQ-ACK/NACK bits corresponding to each downlink time unit may be determined according to the maximum number of transmittable coding blocks CB per downlink time unit.

Preferably, the number of HARQ-ACK/NACK bits corresponding to each downlink time unit may be determined according to the number of the most transmittable coding block groups CB-group per downlink time unit. If the base station configures the dynamic switching that the UE can perform the scheduling based on the coding block group and the scheduling based on the transmission block group, the bit number of the HARQ-ACK of the UE is always determined according to the maximum number of the coding block groups which can be transmitted. For example, the base station configures the UE with coding block group based scheduling, and configures two types of DCI, one DCI is used for scheduling coding block groups, and one DCI is used for scheduling transport blocks. The base station can dynamically adopt any kind of DCI to schedule the UE, but the UE always determines the number of the coding block groups which can be sent at most when feeding back the HARQ-ACK. Assuming that the number of the maximum transmittable coding block groups is 4, when the base station schedules transmission of one TB by scheduling of a transport block, the UE still feeds back 4 bits of HARQ-ACK, wherein the 1 st bit is generated according to the decoding result of the TB, and the other 3 bits are space occupying bits, such as NACK. If the active carrier can support the transmission of 2 transport blocks and the coding block group based scheduling is configured, one implementation is that the HARQ-ACK bit is always equal to (2 x the number of the most transmittable coding block groups) regardless of the coding block group or transport block group based dynamic scheduling of the base station, and another implementation is that the HARQ-ACK bit is always equal to (the number of the most transmittable coding block groups) regardless of the coding block group or transport block group based dynamic scheduling of the base station, which can be independent of the spatial dimension binding configured by RRC signaling in the existing system, e.g., without RRC configuration signaling, once the coding block group based scheduling is configured, the HARQ-ACK bit is always equal to (the number of the most transmittable coding block groups) or there is an additional RRC configuration signaling independent of the existing signaling.

Preferably, the control signaling may include information indicating that the number of HARQ-ACK/NACK bits corresponding to each downlink time unit is determined according to the number of the transport blocks that can be transmitted at most in each downlink time unit, or according to the number of the coding block groups that can be transmitted at most in each downlink time unit.

According to an exemplary embodiment, the size of the HARQ-ACK/NACK codebook corresponding to the uplink time unit may be obtained by multiplying the size of the feedback window corresponding to the uplink time unit by the number of HARQ-ACK/NACK bits corresponding to each downlink time unit.

For example, if N bits are used in a Downlink Control Instruction (DCI) to indicate HARQ-ACK/NACK timing (i.e. time relationship between PDSCH and HARQ-ACK/NACK), then M =2^ N, i.e. ACK/NACK of PDSCH of M downlink time units can be fed back at most in the same uplink time unit. Then the ACK/NACK codebook size is a function of M. For example, the codebook size is M × Z, where Z is the number of HARQ-ACK/NACK bits corresponding to each downlink time unit.

According to another exemplary embodiment, if the number of HARQ-ACK/NACK bits in each downlink time unit is not equal, for example, some downlink time units are HARQ-ACK/NACK feedback based on a transport block, and some downlink time units are HARQ-ACK/NACK feedback based on a coding block group, the number of HARQ-ACK/NACK feedback bits of all downlink time units in a feedback window is added to determine the HARQ-ACK/NACK codebook size.

Preferably, if a part of time units within the value range of the HARQ-ACK/NACK timing indicated in the downlink control command (DCI) are time units that do not transmit the downlink PDSCH, the size of the HARQ-ACK/NACK codebook is determined after the time units need to be removed. For example, in a TDD system, if the time unit is configured as an uplink time unit. For example, 3 bits indicate HARQ-ACK/NACK timing, which may indicate that the difference m-n from time unit n of PDSCH to time unit m of the corresponding HARQ-ACK/NACK is k ₀ +0，k ₀ +1，…，k ₀ +7. If the time unit m-k ₀ And m-k ₀ And-1 is an uplink time unit, the HARQ-ACK/NACK codebook size is determined according to M = (8-2) = 6.

Preferably, the time unit that does not send the PDSCH may be determined through semi-static signaling, such as RRC signaling, or may be determined through dynamic signaling, such as DCI indication.

Preferably, when calculating the HARQ-ACK/NACK codebook size, the size of the feedback window corresponding to the uplink time element is obtained by removing a downlink time element that is indicated by a signaling and must not transmit the PDSCH.

Preferably, when calculating the size of the HARQ-ACK/NACK codebook, the size of the feedback window corresponding to the uplink time unit is obtained by removing the downlink time unit indicated by the semi-static signaling that must not transmit the PDSCH, and the size of the feedback window corresponding to the uplink time unit is obtained by not removing the downlink time unit indicated by the dynamic signaling that must not transmit the PDSCH. The method has the advantage of avoiding the problem that the size of the ACK/NACK code book generated by the user equipment is inconsistent with the size of the ACK/NACK code book expected by the base station due to the fact that the user equipment fails to detect or mistakenly detects the dynamic signaling.

According to an aspect of the second embodiment of the present invention, in step 102, the user equipment may determine the size of the HARQ-ACK/NACK codebook corresponding to the uplink time unit based on the size of the HARQ-ACK/NACK codebook configured by the base station.

The control signaling may further include a total number of HARQ processes supportable in one uplink time unit and a HARQ process ID, or the control signaling further includes a HARQ process ID, and the total number of HARQ processes supportable in one uplink time unit is standard predefined. Accordingly, the user equipment may generate a HARQ-ACK/NACK codebook corresponding to an uplink time unit based on a HARQ process (HARQ process).

And then multiplying the minimum bit number which can be occupied by the HARQ-ACK/NACK corresponding to each HARQ process by the ID i of the HARQ process of each downlink time unit corresponding to the uplink time unit, such as i =0,1, \8230: < L-1 >, and obtaining the starting point Y i, i =0,1, \8230: < L-1 > of the HARQ-ACK/NACK corresponding to each downlink time unit corresponding to the uplink time unit in the HARQ-ACK/NACK codebook.

When the position of the HARQ-ACK/NACK corresponding to the invalid HARQ process is occupied by the HARQ-ACK/NACK corresponding to the valid HARQ process, the user equipment determines the number of bits of the HARQ-ACK/NACK corresponding to the invalid HARQ process as the difference between the number of bits that the HARQ-ACK/NACK corresponding to each HARQ process can occupy and the number of bits that the HARQ-ACK/NACK corresponding to the valid HARQ process occupies. For example, the number of ACK/NACK bits Z' of an HARQ process that does not receive a PDSCH in a corresponding time unit (i.e., an invalid HARQ process) is determined according to whether it is occupied by ACK/NACK of a valid HARQ process. Z' = Y if not occupied by ACK/NACK for active HARQ processes. If occupied by ACK/NACK for an active HARQ process, assuming the number of occupied bits is Y1, then Z' = Y-Y1. When Y = Y1, Z' =0.

According to another aspect of the second exemplary embodiment, the user equipment determines downlink time unit indexes of downlink time units corresponding to the uplink time units based on the information on the HARQ-ACK/NACK timing, wherein the downlink time unit indexes of the downlink time units corresponding to the uplink time units respectively indicate relative time sequences of the downlink time units corresponding to the uplink time units in a feedback window; and determining the position of the HARQ-ACK/NACK corresponding to each downlink time unit corresponding to the uplink time unit in the HARQ-ACK/NACK codebook according to a descending order (the HARQ-ACK/NACK order of the downlink time unit is in an opposite order to the feedback timing indicated in the DCI transmitted by the downlink time unit) or a descending order (the HARQ-ACK/NACK order of the downlink time unit is in the same order to the feedback timing indicated in the DCI transmitted by the downlink time unit) based on the relative time sequence.

For example, 2 bits in DCI indicate HARQ-ACK/NACK timing (i.e., time relationship of PDSCH and HARQ-ACK/NACK), assuming that PUCCH where HARQ-ACK/NACK is fed back is locatedIf the uplink time unit is m, the downlink time unit m- (k) ₀ + 3) -downlink time unit m- (k) ₀ ) It is possible to feed back ACK/NACK in the uplink time unit m, for example, 2 bits in DCI are 11, 10, 01, 00, respectively. When the base station schedules, 1 or more of the 4 downlink time units may be scheduled, and when the downlink time units are scheduled, 2 bits in the DCI may take any value. However, as long as there is at least one HARQ-ACK/NACK of the downlink time unit falling in the uplink time unit m, the UE determines the size of the HARQ-ACK/NACK codebook according to the 4 downlink time units, and determines the position of the HARQ-ACK/NACK bit of the PDSCH in the HARQ-ACK/NACK codebook according to the relative time sequence of the actually received downlink time unit in the 4 downlink time units.

For example, the HARQ-ACK/NACK codebook size of the PUCCH in uplink time unit M is M × Z =4 × 2=8, that is, the HARQ-ACK/NACK codebook size is 8. If the HARQ-ACK/NACK feedback time indicated by the DCI is in the order from large to small, the 1,2 bits are time units m- (k) ₀ + 3) HARQ-ACK/NACK for PDSCH, with the 3,4 th bit being the time unit m- (k) ₀ + 2) of the PDSCH, and so on.

After determining the position of HARQ-ACK/NACK corresponding to each downlink time unit corresponding to the uplink time unit in the HARQ-ACK/NACK code book by the method, the user equipment respectively generates the HARQ-ACK/NACK code book according to an effective downlink time unit and an ineffective downlink time unit. The valid downlink time element is an uplink time element of the uplink time element, which is an HARQ-ACK/NACK corresponding to the received PDSCH. The invalid downlink time element is a downlink time element in which the PDSCH is not received or an uplink time element in which the PDSCH is received but HARQ-ACK/NACK corresponding to the PDSCH is not the uplink time element.

And generating HARQ-ACK/NACK according to the received PDSCH for the effective downlink time unit, and inserting the HARQ-ACK/NACK generated for the effective downlink time unit into the HARQ-ACK/NACK codebook based on the position of the HARQ-ACK/NACK corresponding to the effective downlink time unit in the HARQ-ACK/NACK codebook.

And aiming at the downlink time unit which does not receive the PDSCH, the user equipment generates HARQ-NACK occupation according to a predefined rule.

And aiming at the uplink time unit which receives the PDSCH but has HARQ-ACK/NACK corresponding to the PDSCH and is not the downlink time unit of the uplink time unit, the user equipment generates HARQ-NACK occupation according to a predefined rule.

Preferably, for a downlink time unit in which the PDSCH is not received, the user equipment generates HARQ-NACK placeholders according to a predefined rule. However, for the uplink time unit in which the PDSCH is received but the HARQ-ACK/NACK corresponding to the PDSCH is not the downlink time unit of the uplink time unit, the ue still generates HARQ-ACK/NACK according to the PDSCH decoding result, and inserts the generated HARQ-ACK/NACK into the HARQ-ACK/NACK codebook.

For example, fig. 8 is a diagram of uplink and downlink mapping based on downlink time units according to a second exemplary embodiment of the present invention.

Referring to fig. 8, for example, 2 bits in DCI indicate a time difference of PDSCH to feedback HARQ-ACK/NACK, which may be 3,4,5 and 6. Assuming that the number of HARQ-ACK/NACK bits fed back per downlink time unit Z =2, the HARQ-ACK/NACK codebook size is M × Z =8. The 2-bit indication in the DCI scheduling downlink time unit m is 10, that is, HARQ-ACK/NACK is fed back in uplink time unit m +5, the 2-bit indication in the DCI scheduling downlink time unit m +1 is 01, that is, HARQ-ACK/NACK is fed back in uplink time unit m +5, and the 2-bit indication in the DCI scheduling downlink time unit m +2 is 01, that is, HARQ-ACK/NACK is fed back in uplink time unit m + 6. Then, for the uplink time unit m +5, the first two bits of the ACK/NACK codebook, corresponding to downlink time unit m-1, since no data is scheduled, a 2-bit HARQ-NACK results. For the middle 4 bits of the HARQ-ACK/NACK codebook, the HARQ-ACK/NACK result is determined according to the received demodulation results of the PDSCH of the downlink time unit m and m +1, respectively, and for the last two bits of the HARQ-ACK/NACK codebook, since the HARQ-ACK/NACK of the PDSCH of the downlink time unit m +2 is fed back in the uplink time unit m +6, a 2-bit HARQ-NACK is generated. For the uplink time unit m +6, the first four bits of the HARQ-ACK/NACK codebook are NACK, because the downlink time unit for feeding back HARQ-ACK/NACK corresponding to the downlink time units m and m +1 is m +5.

According to another aspect of the second embodiment of the present invention, the control signaling may further include information indicating a relative time order of the currently scheduled downlink time unit in the feedback window corresponding to the uplink time unit. Therefore, the user equipment may determine, based on the information of the relative time order of all scheduled downlink time units corresponding to the uplink time unit in the feedback window corresponding to the uplink time unit, the positions of HARQ-ACK/NACKs in the HARQ-ACK/NACK codebook corresponding to all scheduled downlink time units corresponding to the uplink time unit, where a currently scheduled downlink time unit refers to a time unit in which the user equipment receives a PDSCH from the base station in a current downlink time unit.

Preferably, when the base station configures carrier aggregation for the ue, if the size of the feedback window on each carrier is different, the size of the HARQ-ACK/NACK codebook is determined according to the maximum length of each feedback window. For example, the base station configures 2 serving cells for the ue, where the size of the feedback window of one serving cell is 4, and the size of the feedback window of another serving cell is 2, and then determines the size of the HARQ-ACK codebook according to the number of the serving cells 2 × the number of HARQ-ACK bits of each downlink time unit, where the size of each carrier feedback window is 4 × the number of the serving cells is 2. For a serving cell with an actual feedback window size of 2, HARQ-ACK feedback of length 4 is achieved by generating placeholder bits.

Preferably, the control signaling may further include a first type DAI, where the first type DAI indicates one of the following information: relative time sequence of the current scheduled downlink time unit in all the scheduled downlink time units corresponding to the uplink time unit, and bit position of HARQ-ACK/NACK bit of the current scheduled downlink time unit in the HARQ-ACK/NACK code book. Therefore, the user equipment can determine the position of HARQ-ACK/NACK corresponding to each downlink time unit of all the scheduled downlink time units corresponding to the uplink time unit in the HARQ-ACK/NACK code book based on the first type DAI values of all the scheduled downlink time units corresponding to the uplink time unit.

For example, fig. 9 is another schematic diagram of uplink and downlink mapping based on downlink time units according to the second exemplary embodiment of the present invention.

Referring to fig. 9, the bit indicating the HARQ-ACK/NACK feedback time in dci is 2 bits, indicating that the time difference between the HARQ-ACK/NACK and the PDSCH is 1,2,3,4, respectively. If the DCI of the PDSCH scheduling the downlink time unit n indicates that the feedback time difference of the HARQ-ACK/NACK is 2, the n +3 feeds back the HARQ-ACK/NACK, the DCI of the PDSCH scheduling the downlink time unit n +1 indicates that the feedback time difference of the HARQ-ACK/NACK is 1, the n +2 feeds back the HARQ-ACK/NACK, and the DCI of the PDSCH scheduling the downlink time unit n +2 indicates that the feedback time difference of the HARQ-ACK/NACK is 1, the n +3 feeds back the HARQ-ACK/NACK. Then, HARQ-ACK/NACK of two downlink time units is fed back on the uplink time unit n +3, and then the first type DAI indicated in the DCI of the downlink time unit n and time unit n +2 is DAI =1 and DAI =2, respectively, and the first type DAI =1 indicated in the DCI of the downlink time unit n + 1.

Preferably, in the control signaling, the first type of DAI may be jointly encoded with information on HARQ-ACK/NACK timing.

When the HARQ-ACK/NACK feedback time indication value is the maximum value, for example, 2 bits indicate that the HARQ-ACK/NACK time difference is 1-4, then, assuming that the DCI scheduling downlink time unit n indicates that the HARQ-ACK/NACK time difference is 4, the first type DAI is definitely 1, that is, the current downlink time unit must be the first downlink time unit feeding HARQ-ACK/NACK back in uplink time unit n +4, because the downlink time unit before downlink time unit n cannot be mapped to uplink time unit n +4. And when the indicated time difference of the HARQ-ACK/NACK is 3, the first type of DAI must be 1 or 2, that is, there are only two possibilities, one is that the current downlink time unit n is the first downlink time unit for feeding back the HARQ-ACK/NACK in the uplink time unit n +3, or the downlink time unit n-1 is the first downlink time unit for feeding back the HARQ-ACK/NACK in the uplink time unit n +3, and the downlink time unit n is the second downlink time unit for feeding back the HARQ-ACK/NACK in the uplink time unit n + 3. By analogy, when the indicated HARQ-ACK/NACK time difference is 1, the DAI of the first type may be 1,2,3, or 4. Then, the combination of HARQ-ACK/NACK timing and first type DAI is 10 instead of 16 in total. If 4-bit joint coding is used, the remaining 6 states can be used for other purposes.

To further compress the bits, part of the combination of the first type DAI and HARQ-ACK/NACK timing may be removed. For example, 3 bits may be employed to jointly indicate the first type of DAI and the HARQ-ACK/NACK feedback time. Assuming that the value range of the HARQ-ACK/NACK feedback delay is 3 to 6, the table shows the correlation of the joint coding for the downlink time unit n.

Watch 1

After determining the positions of the HARQ-ACK/NACKs corresponding to the downlink time units corresponding to the uplink time unit in the HARQ-ACK/NACK codebook in this way, the ue may sequentially insert HARQ-ACK/NACKs corresponding to all scheduled downlink time units from the starting position of the HARQ-ACK/NACK codebook according to the size of the relative time order indicated by the first class DAIs of all scheduled downlink time units corresponding to the uplink time unit, and insert placeholders at subsequent positions.

In addition, when the discontinuous first type of DAI is detected, the user equipment may determine that a PDSCH of a downlink time unit corresponding to the missing first type of DAI is missed, generate HARQ-NACK for the missed PDSCH, and insert the generated HARQ-NACK into a position in the HARQ-ACK/NACK codebook corresponding to a relative time order indicated by the missing first type of DAI.

The third exemplary embodiment of the present invention is described below。

According to an aspect of the third exemplary embodiment of the present invention, the size of the HARQ-ACK/NACK codebook generated by the user equipment is not fixed, but corresponds to the number of downlink time units of the PDSCH that require feedback of HARQ-ACK/NACK in the uplink time unit.

Preferably, the control signaling may include a first type of DAI, which is carried through DCI. Wherein the first type of DAI indicates one of the following information: relative time sequence of the current scheduled downlink time unit in all the scheduled downlink time units corresponding to the uplink time unit, and bit position of HARQ-ACK/NACK bit of the current scheduled downlink time unit in the HARQ-ACK/NACK code book. The number of HARQ-ACK/NACK bits of each downlink time unit is assumed to be N ₀ According to said first type DAI value X ₀ Determining the starting point of the HARQ-ACK/NACK bit of the downlink time unit in the HARQ-ACK/NACK codebook as the Xth point ₀ *N ₀ 1 bit. E.g. N ₀ And (2). Then, when the first type DAI =1, the HARQ-ACK/NACK bit corresponds to the 1,2 th bit in the HARQ-ACK/NACK codebook, and so on, and when the first type DAI =4, the HARQ-ACK/NACK bit corresponds to the 7,8 th bit in the HARQ-ACK/NACK codebook. Accordingly, the user equipment may also determine the size of the HARQ-ACK/NACK codebook based on the first type DAI. Specifically, the user equipment determines the size of the HARQ-ACK/NACK codebook by combining the maximum value in the first class DAIs of all scheduled downlink time units corresponding to the uplink time unit and the HARQ-ACK/NACK bit number corresponding to each downlink time unit. After determining the size of the HARQ-ACK/NACK codebook in this way, the user equipment may further determine, based on the values of the first class DAI for each of all scheduled downlink time units corresponding to the uplink time unit, the position of the HARQ-ACK/NACK in the HARQ-ACK/NACK codebook corresponding to each of all scheduled downlink time units corresponding to the uplink time unit.

Preferably, the first type of DAI may also indicate a starting position of HARQ-ACK/NACK bits corresponding to a currently scheduled PDSCH in a HARQ-ACK/NACK codebook. For example, the value X of the first type DAI of the second downlink time unit being scheduled ₀ =5 indicates that the starting position of the HARQ-ACK/NACK bit of this downlink time unit in the HARQ-ACK/NACK codebook is 5.I.e. X ₀ Has already been converted to N ₀ And converting into the original value. The advantage of this method is that it can support the situation that the number of HARQ-ACK/NACK bits of each downlink time unit is not equal, i.e. N of each downlink time unit ₀ May be different. For example, the first downlink time unit is HARQ-ACK/NACK based on coding block group feedback, N ₀ =4, and the second downlink time unit is HARQ-ACK/NACK based on transport block set feedback, N ₀ And =1. As mentioned above, the value X of the DAI of the first type for the second downlink time unit ₀ =5. That is, the first type DAI is counted in units of coding block groups, not according to the PDCCH in the prior art. Similarly, when the UE is configured to operate in carrier aggregation mode, this method can support N per downlink time unit/downlink carrier ₀ In different cases. Since the maximum value range of the first type DAI of this method is extended, more bits are required. For example, the first type DAI of this method requires 3 bits, or 4 bits, compared to the 2-bit first type DAI of the existing LTE.

If at least one working carrier can support the transmission of 2 transmission blocks, the first type DAI based on the coding block group counting can work at least in the following three ways, (1) when the first type DAI counts a downlink time unit, the downlink time unit is not distinguished into one or two transmission blocks, but the counting is carried out according to the total number of coding blocks of all the transmission blocks of the downlink time unit, and the number of the fed-back HARQ-ACK bits is consistent with the first type DAI. (2) If the base station configures the binding of spatial dimension, the first type DAI counts a downlink time unit according to the total number of coding blocks of a transmission block, and performs AND operation on HARQ-ACK of the two transmission blocks when the two transmission blocks are scheduled. In the above example, it is assumed that the first downlink time unit is HARQ-ACK/NACK based on coding block group feedback and 2 transport blocks are scheduled, the second downlink time unit is HARQ-ACK/NACK based on transport block group feedback and one transport block, N, is scheduled ₀ And =1. For the first downlink time unit, the HARQ-ACK ratio of each transport block before bundlingNumber of bits N ₀ =4, after binding, still feeding back N ₀ =4 bits. Value X of DAI of first type for second downlink time unit ₀ =5 still indicates that the starting position of the HARQ-ACK/NACK bit for this downlink time unit in the HARQ-ACK/NACK codebook is 5. (3) If the base station is not bound with the configured space dimension, when the first type DAI counts a downlink time unit, counting is carried out according to the total number of coding blocks of a transmission block, but the number of the fed-back HARQ-ACK bits is 2 times of the counting. In the above example, it is assumed that the first downlink time unit is HARQ-ACK/NACK based on coding block group feedback and 2 transport blocks are scheduled, the second downlink time unit is HARQ-ACK/NACK based on transport block group feedback and one transport block, N, is scheduled ₀ =1. For the first downlink time unit, the number of HARQ-ACK bits of each transport block is N ₀ =4, total feedback 2 × n ₀ One bit. For the second downlink time unit, the number of HARQ-ACK bits N of the scheduled transport block ₀ =1, and 1 bit placeholder bit is transmitted, feeding back 2 bits in total. Second downstream time unit DAI value X of first type ₀ =5 said downlink time unit HARQ-ACK/NACK bit start position in HARQ-ACK/NACK codebook is 2 x ₀ -1. The total number of bits of the HARQ-ACK/NACK codebook is 10.

Preferably, the first type of DAI determined in the above manner may be used only for dynamically determining HARQ-ACK/NACK code books for PDSCHs of multiple carriers or time units, and may not be used when HARQ-ACK/NACK code books for PDSCHs of multiple carriers or time units are semi-statically determined. For example, the first type of DAI based on PDSCH counting in the prior art may be used, or no DAI may be used.

Preferably, the control signaling further includes a second type of DAI, and the second type of DAI is carried by DCI. According to an exemplary embodiment, the DAI of the second type indicates a total number of all scheduled downlink time units corresponding to the uplink time unit. In this case, the user equipment is accessibleAnd determining the size of the HARQ-ACK/NACK code book by combining the value of the second type of DAI and the HARQ-ACK/NACK bit number corresponding to each downlink time unit. Suppose the HARQ-ACK/NACK bit number of each downlink time unit is N ₀ The DAI of the second type has a value Y ₀ Then the size of the HARQ-ACK/NACK codebook is Y ₀ *N ₀ . In this way, the size of the HARQ-ACK/NACK codebook is not fixed, but corresponds to the total number of downlink time units of all scheduled downlink time units corresponding to the uplink time unit.

For example, fig. 10 is a schematic diagram of uplink and downlink mapping based on downlink time units according to a third exemplary embodiment of the present invention.

Referring to fig. 10, the bit indicating the HARQ-ACK/NACK feedback time in dci is 2 bits, indicating that the time difference between the HARQ-ACK/NACK and the PDSCH is 1,2,3,4, respectively. If the DCI of the PDSCH scheduling the downlink time unit n indicates that the HARQ-ACK/NACK feedback time difference is 3, then n +3 feeds back the HARQ-ACK/NACK, the DCI of the PDSCH scheduling the downlink time unit n +1 indicates that the HARQ-ACK/NACK feedback time difference is 1, then n +2 feeds back the HARQ-ACK/NACK, and the DCI of the PDSCH scheduling the downlink time unit n +2 indicates that the HARQ-ACK/NACK feedback time difference is 1, then n +3 feeds back the HARQ-ACK/NACK. Then, HARQ-ACK/NACK for two downlink time units is fed back on the uplink time unit n +3, and then the second type DAI =2 indicated in the DCI for the downlink time unit n and time unit n +2 (it is assumed that 00 represents DAI =1, i.e., 1 downlink time unit, and 01 represents DAI =2, i.e., 2 time units), and the second type DAI =1 indicated in the DCI for the downlink time unit n + 1.

According to another exemplary embodiment, the DAI of the second type indicates a total number of downlink time units from a first downlink time unit to a current downlink time unit among all scheduled downlink time units corresponding to the uplink time unit. In this case, the ue may determine the size of the HARQ-ACK/NACK codebook by combining the maximum value of the second class DAIs of all scheduled downlink time units corresponding to the uplink time unit with the number of HARQ-ACK/NACK bits corresponding to each downlink time unit. In this way, the size of the HARQ-ACK/NACK codebook is not fixed, but corresponds to the total number of downlink time units of all scheduled downlink time units corresponding to the uplink time unit. In this case, when the user equipment configures only one serving cell, i.e., does not operate in carrier aggregation, the first and second types of DAIs are the same. Only one DAI needs to be indicated in the DCI.

For example, fig. 11 is another schematic diagram of uplink and downlink mapping based on downlink time units according to the third exemplary embodiment of the present invention.

Referring to fig. 11, the bit indicating the HARQ-ACK/NACK feedback time in dci is 2 bits, indicating that the time difference between the HARQ-ACK/NACK and the PDSCH is 1,2,3,4, respectively. If the DCI of the PDSCH scheduling the downlink time unit n indicates that the HARQ-ACK/NACK feedback time difference is 3, then n +3 feeds back the HARQ-ACK/NACK, the DCI of the PDSCH scheduling the downlink time unit n +1 indicates that the HARQ-ACK/NACK feedback time difference is 1, then n +2 feeds back the HARQ-ACK/NACK, and the DCI of the PDSCH scheduling the downlink time unit n +2 indicates that the HARQ-ACK/NACK feedback time difference is 1, then n +3 feeds back the HARQ-ACK/NACK. Then, HARQ-ACK/NACK of two downlink time units is fed back in the uplink time unit n +3, and then the second type DAI =1 indicated in the DCI of the downlink time unit n (assuming 00 represents DAI =1, i.e., 1 downlink time unit, and 01 represents DAI =2, i.e., 2 time units), the second type DAI =1 indicated in the DCI of the downlink time unit n +1, and the second type DAI =2 indicated in the DCI of the downlink time unit n + 2.

According to another exemplary embodiment, the DAI of the second type may indicate the total number of bits of the HARQ-ACK/NACK codebook. I.e. the value Y of the DAI of the second type ₀ Has already been converted to N ₀ Reduced to N and capable of supporting different downlink time units/downlink carriers ₀ Unequal, i.e. counted in CBG units. In this case, the user equipment may determine the size of the HARQ-ACK/NACK codebook based on the number of bits indicated by the DAI of the second type.

Preferably, in the control signaling, the first type DAI, the second type DAI, and the information on HARQ-ACK/NACK timing may be jointly encoded.

For example, 5 bits may be employed to jointly indicate the first class, the second class of DAI and the HARQ-ACK/NACK feedback time. 1 bit can be saved compared with the method that 2 bits are respectively used for indicating the first type of DAI,2 bits are used for indicating the second type of DAI, and 2 bits are used for indicating the HARQ-ACK/NACK feedback time. Thus, table two shows the relationship of the joint coding information for the downlink time unit n.

Watch two

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For example, fig. 12 is another schematic diagram of uplink and downlink mapping based on downlink time units according to the third exemplary embodiment of the present invention.

Referring to fig. 12, it is assumed that the indicated HARQ-ACK/NACK timing range in DCI is 3 to 6, and the maximum total number of downlink time units corresponding to the indicated HARQ-ACK/NACK feedback in the same uplink time unit is 4. Then, according to the 5-bit joint coding of table two, for the downlink time unit n, the 5-bit indication is 00010, that is, the HARQ-ACK/NACK feedback is the uplink time unit n +6, the downlink time unit n is the first downlink time unit for feeding the HARQ-ACK/NACK feedback in the uplink time unit n +6, that is, the first type DAI =1, and the total number of downlink time units for feeding the HARQ-ACK/NACK feedback in the uplink time unit n +6 is 3, that is, the second type DAI =3. For the downlink time unit n +2, the 5-bit indication is 01101, that is, the HARQ-ACK/NACK feedback is uplink time unit n +6, the downlink time unit n +2 is the second downlink time unit for feeding the HARQ-ACK/NACK back in the uplink time unit n +6, that is, DAI =2 of the first type, and the total number of downlink time units corresponding to the HARQ-ACK/NACK feedback in the uplink time unit n +6 is 3, that is, DAI =3 of the second type. For the downlink time unit n +3,5 bits are indicated as 10010, i.e., HARQ-ACK/NACK feedback is uplink time unit n +6, downlink time unit n +3 is the third downlink time unit for feeding HARQ-ACK/NACK feedback in uplink time unit n +6, i.e., DAI =3 of the first type, and the total number of downlink time units for feeding HARQ-ACK/NACK feedback in uplink time unit n +6 is 3, i.e., DAI =3 of the second type.

For another example, fig. 13 is another schematic diagram of uplink and downlink mapping based on downlink time units according to the third exemplary embodiment of the present invention.

Referring to fig. 13, it is assumed that the indicated HARQ-ACK/NACK timing range in DCI is 3 to 6, and the maximum total number of downlink time units corresponding to the indicated HARQ-ACK/NACK feedback in the same uplink time unit is 4. Then, according to the 5-bit joint coding of table two, for the downlink time unit n, the 5-bit indication is 00001, i.e. HARQ-ACK/NACK feedback is the uplink time unit n +6, the downlink time unit n is the first downlink time unit for feeding HARQ-ACK/NACK feedback in the uplink time unit n +6, i.e. the first type DAI =1, and the total number of downlink time units for feeding HARQ-ACK/NACK back in the uplink time unit n +6 is 2, i.e. the second type DAI =2. For the downlink time unit n +2, the 5-bit indication is 00000, that is, the HARQ-ACK/NACK feedback is the uplink time unit n +8, the downlink time unit n +2 is the first downlink time unit for feeding the HARQ-ACK/NACK back in the uplink time unit n +8, that is, the DAI =1 in the first class, and the total number of downlink time units for feeding the HARQ-ACK/NACK back in the uplink time unit n +8 is 1, that is, the DAI =1 in the second class. For the downlink time unit n +3, the 5-bit indication is 10001, that is, the HARQ-ACK/NACK feedback is the uplink time unit n +6, the downlink time unit n +2 is the second downlink time unit for feeding the HARQ-ACK/NACK back in the uplink time unit n +6, that is, the DAI =2 in the first type, and the total number of downlink time units for feeding the HARQ-ACK/NACK back in the uplink time unit n +6 is 2, that is, the DAI =2 in the second type.

It is noted that the number of bits of the first type of DAI and/or the second type of DAI is limited, for example 2 bits, but may represent a value greater than 4 in a modulo manner. For example, when the number M of downlink time units corresponding to the same uplink time unit feedback HARQ-ACK/NACK is indicated to be greater than the range indicated by the DAI bit, the corresponding DAI value in the table in this embodiment is M modulo M _ DAI. For example, M =8, but the DAI is only 2 bits, then DAI =3 in the table may represent 3 and 7.

Preferably, in the control signaling, a third type DAI may be included, where the content of the third type DAI indication is the same as the content of the second type DAI indication, or the third type DAI indicates the total number of bits of the HARQ-ACK/NACK codebook expected to be received by the base station, and the total number of bits of the HARQ-ACK/NACK corresponding to the PDSCH actually scheduled by the base station is less than or equal to the expected total number of bits. For example, the control signaling DCI for scheduling uplink transmission includes a third type of DAI, and the control signaling DCI for scheduling downlink transmission includes a first type of DAI and a second type of DAI. When HARQ-ACK is sent on PUSCH, if PUSCH needs to carry out rate matching according to HARQ-ACK code book, the size of the HARQ-ACK code book is indicated by third type DAI. In order to allow the UE to have enough time for rate matching, it may be specified that, for a PDSCH transmitting HARQ-ACK on the same PUSCH, the PDSCH is scheduled, and the DCI including the first and second types of DAIs cannot be later than the DCI including the PUSCH and the third type of DAI, or the time difference between the DCI including the first and second types of DAIs and the PUSCH cannot be less than a predefined value, or the time difference between the DCI including the first and second types of DAIs and the DCI including the third type of DAI is not limited, but the base station needs to ensure that the size of the HARQ-ACK codebook indicated by the second type of DAI does not exceed the size of the HARQ-ACK codebook indicated by the third type of DAI.

In addition, the downlink time units corresponding to the HARQ-ACK/NACK fed back in the same uplink time unit according to the HARQ-ACK/NACK timing M = M at most ₁ And is described as an example. However, the above-described scheme of joint coding is equally applicable to M HARQ-ACK/NACK timings>The downlink time unit corresponding to HARQ-ACK/NACK fed back by the same uplink time unit is at most M ₁ The case (1).

According to another aspect of the present invention, when generating the HARQ-ACK/NACK codebook, when the total number of bits of the uplink control signaling including at least HARQ-ACK/NACK to be fed back in the uplink time unit exceeds the maximum number of bits of the uplink control signaling that can be carried by the PUCCH resource configured by the base station, the ue may compress the HARQ-ACK/NACK bits to be fed back in the uplink time unit according to a predefined rule. Here, the maximum bit number of HARQ-ACK/NACK that can be carried by PUCCH resources configured by the base station is predefined by the standard, or is determined by physical resources occupied by PUCCH and a predefined coding rate, or is determined by the format of PUCCH. One implementation is to compress the HARQ-ACK/NACK feedback of a coding block/coding block group into HARQ-ACK/NACK of a transport block. Assuming that each transmission block can be divided into at most Ncb coding block groups, when the total number of HARQ-ACK/NACK to be fed back exceeds the maximum bit number of HARQ-ACK/NACK that can be carried by PUCCH resources configured by the base station, if all the scheduled Ncb ' coding block groups are correctly decoded (where Ncb ' is less than or equal to Ncb), the entire transmission block is considered to be correctly transmitted, and 1-bit ACK is generated, and if at least one Ncb ' coding block group is not correctly decoded, the entire transmission block is considered to be erroneously transmitted, and 1-bit HARQ-NACK is generated.

According to another aspect of the present invention, when generating the HARQ-ACK/NACK codebook, when the total number of bits of the uplink control signaling including at least HARQ-ACK/NACK to be fed back in the uplink time unit exceeds the maximum number of bits of the uplink control signaling that can be carried by the PUCCH resource configured by the base station, the uplink control signaling is transmitted in the uplink time unit using the next larger PUCCH resource capable of carrying the total number of bits of the uplink control signaling to be fed back. For example, the base station semi-statically configures 4 PUCCH resources for the user equipment, and the maximum bit numbers that can carry ACK/NACK are Na1, na2, and Na2, respectively. And the base station instructs the user equipment to adopt the second PUCCH resource, but the user equipment finds that the total number of the ACK/NACK required to be fed back exceeds Na1 but does not exceed Na2, and the user equipment adopts the third PUCCH resource.

According to another aspect of the present invention, when generating the HARQ-ACK/NACK codebook, when the total bit number of the uplink control signaling including at least HARQ-ACK/NACK to be fed back in the uplink time unit exceeds the maximum bit number of the uplink control signaling that can be carried by the PUCCH resource configured by the base station, the ue is in the current downlink time unit or at least the last downlink corresponding to the uplink time unitAnd the inter-unit is used for receiving downlink scheduling information of a PUCCH resource which indicates a new total bit number capable of bearing the uplink control signaling to be fed back from the base station and sending the uplink control signaling in the uplink time unit by using the new PUCCH resource. For example, the base station semi-statically configures 4 kinds of PUCCH resources for the user equipment, and the maximum bit number that can carry HARQ-ACK/NACK is N _a1 ，N _a1 ，N _a2 ，N _a2 . In the first and second downlink time units, the base station indicates the user equipment to adopt the second PUCCH resource, but in the third downlink time unit, the base station indicates the user equipment to adopt the third PUCCH resource, and the user equipment adopts the third PUCCH resource.

According to another aspect of the present invention, when generating the HARQ-ACK/NACK codebook, when the total bit number of HARQ-uplink control signaling to be fed back in the uplink time unit exceeds the maximum bit number of uplink control signaling that can be carried by the PUCCH resource configured by the base station, the user equipment abandons sending HARQ-ACK/NACK of the downlink time unit with low priority, so that the total bit number of the sent uplink control signaling does not exceed the maximum bit number of uplink control signaling that can be carried by the PUCCH resource configured by the base station. For example, when there are different traffic types, the priority of the PDSCH of the eMBB is lower than the priority of the PDSCH of the URLLC. Or the priority of the PDSCH scheduled by the first DCI format is lower than that of the PDSCH scheduled by the second DCI format. Preferably, the control signaling may also include other uplink control signaling, such as channel state information.

It should be noted that, in the above embodiment, when the HARQ-ACK/NACK fed back in one uplink time unit comes from only one downlink time unit, one implementation manner is to determine the HARQ-ACK/NACK codebook and the HARQ-ACK/NACK bitmap in the same manner as in the above embodiment. Another way to achieve this is to generate the codebook only in terms of HARQ-ACK/NACK for one downlink time unit. When the codebook is generated according to HARQ-ACK/NACK of a downlink time unit, the HARQ-ACK/NACK codebook may be determined according to the number of coding blocks/coding block groups actually scheduled. For example, the PDSCH transmitted in one downlink time unit may have a maximum of N coding block groups, and the HARQ-ACK/NACK feedback has a maximum of N bits. When only HARQ-ACK/NACK of one downlink time unit is fed back in one uplink time unit, the user terminal feeds back k bits of HARQ-ACK/NACK, k is the number of actually scheduled coding block groups, and k is less than or equal to N. However, when there is a plurality of HARQ-ACK/NACK feedbacks in an uplink time unit, the user terminal determines the HARQ-ACK/NACK feedback bit number of each downlink time unit according to N.

According to another aspect of the present invention, when generating the HARQ-ACK/NACK codebook, the same HARQ-ACK/NACK bit number is used for feedback for each downlink time unit and/or downlink carrier that needs to feed back HARQ-ACK/NACK through base station configuration. For example, each downlink time unit and/or each downlink carrier for feeding back HARQ-ACK/NACK in the same uplink time unit may be in different HARQ-ACK/NACK feedback manners, some downlink time units/downlink carriers are HARQ-ACK/NACK feedback based on the coding block group, the number of HARQ-ACK/NACK bits of each downlink time unit/downlink carrier is N1, while other downlink time units/downlink carriers are HARQ-ACK/NACK feedback based on the transmission block, and the number of HARQ-ACK/NACK bits of each downlink time unit/downlink carrier is N2. The base station may configure the UE to feed back the HARQ-ACKs of all downlink time units/downlink carriers according to the same length, for example, the HARQ-ACK/NACK bit number of each downlink time unit/downlink carrier is N1 or N2. For example, if the feedback is configured to be performed according to N2, the compression from N1 bits to N2 bits may be implemented by performing and operation on HARQ-ACK/NACK of multiple coding block groups of one transport block to obtain HARQ-ACK/NACK of one transport block. For another example, if configured to perform feedback according to N1, the extension from N2 bits to N1 bits may be achieved by mapping N2 bits to the first N2 bits of N1, and then occupying the N1-N2 bit pad bits. In this example, if the second type of DAI indicates the total number of downlink time units and/or downlink carriers for which HARQ-ACK/NACK feedback is required, the total number of bits of the HARQ-ACK/NACK codebook is the second type of DAI × N1 or the second type of DAI × N2. For an operating mode in which at least one carrier is configured to support multiple transport blocks, the base station may configure each carrier to perform spatial dimension bundling according to the prior art, that is, when one downlink carrier has two transport blocks that need to feed back HARQ-ACK, the HARQ-ACKs of the two transport blocks perform an and operation. Here, N1 or N2 bits of HARQ-ACK of two transport blocks are anded, so that the number of HARQ-ACK bits of each downlink carrier is N1 or N2, thereby achieving that the total number of bits of the HARQ-ACK/NACK codebook is the second type DAI × N1 or the second type DAI × N2. Or, the base station configures each carrier to perform HARQ-ACK feedback according to two transport blocks, in this embodiment, if the HARQ-ACK/NACK bit number of each downlink time unit/downlink carrier is N1 or N2, the HARQ-ACK/NACK bit number indicates that the total bit number of the two transport blocks is N1 or N2, that is, the total bit number of each transport block is N1/2 or N2/2, and the base station may configure N1 or N2 through signaling, or may configure N1/2 or N2/2 through signaling, where the two may be different in a specific representation form of signaling configuration, but the effect is the same.

According to another aspect of the present invention, in generating the HARQ-ACK/NACK codebook, when the base station schedules only one PDSCH or only one PDSCH satisfying a predefined condition, for example, only a PDSCH scheduled on Pcell and/or a first type DAI =1, if the number c of separable coding block groups determined by the transport block size of the PDSCH is less than the maximum value N of the coding block groups configured by the base station, the user terminal feeds back only c bits of HARQ-ACK/NACK or 2 x c bits of HARQ-ACK/NACK, and when the number of fed back HARQ-ACK/NACK bits and SR are less than or equal to a predefined threshold, for example, the threshold =2, the user terminal will transmit HARQ-ACK/NACK using a PUCCH format for carrying a bit overhead of not more than 2, for example, similar to PUCCH format 1a/1b in an LTE system. In other cases, for example, when HARQ-ACK/NACK of more than one PDSCH needs to be fed back and is a semi-static codebook, the user terminal will determine the HARQ-ACK/NACK codebook according to N and the number of PDSCHs of the HARQ-ACK/NACK that need to be fed back.

According to another aspect of the present invention, in generating the HARQ-ACK/NACK codebook, if there are at least two PDSCHs corresponding to the same transport block in the same HARQ-ACK/NACK codebook, the user terminal may determine the value of HARQ-ACK/NACK according to one of the following two methods when generating the HARQ-ACK/NACK of the PDSCHs:

the first mode: for the same transport block, HARQ-ACK/NACK bits for the chronologically last PDSCH are generated according to the decoding result of the PDSCH, while HARQ-ACK/NACK bit values for all the code block groups of the previous PDSCH are set to a predefined value, for example, to NACK.

The above situation occurs when the base station finds that part of the resources of the previous PDSCH transmission are turned off, and retransmits part of the code block group of the same PDSCH in time, and the HARQ-ACK/NACK of both transmissions are transmitted on the same PUCCH. Since the HARQ-ACK/NACK result generated by the user equipment for the second transmission of the PDSCH is meaningful and the HARQ-ACK/NACK information of the last PDSCH is redundant, power of the PUCCH can be saved by setting all HARQ-ACK/NACK bits of the last PDSCH transmission to NACK.

Moreover, the method can enable the base station to identify whether the user terminal misses the last PDSCH when the HARQ-ACK/NACK of the next PDSCH is NACK, or the user terminal finds that the CRC check of all the coding blocks is correct but the CRC check of the transmission block is wrong when receiving the next PDSCH demodulation. That is, if the user terminal misses the last PDSCH, the user may generate an HARQ-ACK/NACK value for the previously received PDSCH according to the actual demodulation result, and the HARQ-ACK/NACK value at the position of the subsequent PDSCH is all NACKs; if the CRC check of all the coding blocks is correct but the CRC check of the transmission block is wrong, the user sets the HARQ-ACK/NACK of all the PDSCHs as NACK.

Correspondingly, in the base station test, a preferred implementation manner is to perform the bit-to-block or operation on the HARQ-ACK/NACK bits of the two PDSCHs, that is, perform the bit-to-block or operation on the two HARQ-ACK/NACK bits with the same transmission block number, and if one of the two HARQ-ACK/NACK bits is an ACK, it indicates that the transmission block is correctly received. Of course, when the base station finds that the HARQ-ACK of the previous PDSCH is not all NACK, and there is at least one ACK in the HARQ-ACK of the next PDSDCH, the base station may determine that the HARQ-ACK/NACK demodulation may be in error. The base station may perform corresponding processing, such as rescheduling the transport block set with HARQ-ACK/NACK demodulation errors.

For convenience of explanation, a single carrier is taken as an example. As shown in fig. 17, carrier 1 is configured for HARQ-ACK/NACK feedback based on coding block groups, N1=4. It is assumed that the scheduled PDSCHs shown in the figure all correspond to the same PUCCH feedback HARQ-ACK. The base station schedules the retransmission of transport block TB0 at time unit #0, the base station schedules the initial transmission of transport block TB1 at time unit #1, where the 3 rd CBG is knocked out by URLLC, the base station schedules the retransmission of the 3 rd CBG of transport block TB1 again at time unit #3, and the base station schedules the initial transmission of transport block TB2 at time unit # 2. The feedback mode is assumed to be feedback according to the configured maximum number of coding blocks, i.e. N1=4. Assuming that the user terminal successfully detects the PDCCH of the above 4 time elements scheduling PDSCH, the HARQ-ACKs fed back by the end user terminal are in the order of 4 bits of TB0 of time element #0, 4 bits of TB1 of

time element #

1, 4 bits of TB2 of

time element #

2, and 4 bits of TB1 of time element # 3. It is assumed that the user terminal correctly demodulates TB0 and TB2, and correctly demodulates 2 nd and 4 th coding block groups of TB1 of time unit #1, and also correctly demodulates 3 rd coding block group after receiving TB1 of time unit # 3. If the HARQ-ACK/NAKC bit fed back is AAAAAANAAANAAA according to the prior art. However, according to the method of the present invention, the feedback HARQ-ACK/NACK bit is aaaannnnaaanaaa, that is, NACK is fed back although the 2 nd and 4 th coding block groups of TB1 of time unit #1 are correctly decoded, because the feedback at time unit #3 already shows correct demodulation of the 2 nd and 4 th coding blocks and the 3 rd coding block. If the user terminal does not detect the PDCCH of time cell #3, the user terminal should generate a demodulation result when feeding back ACK/NACK for TB1 of time cell #1, i.e., the total HARQ-ACK/NACK bits fed back are aaaaaananaanannn. The base station side can determine whether the user terminal correctly demodulates the corresponding coding block group by bitwise OR of a plurality of HARQ-ACK/NACK of the same TB. For example, in the following example, the time unit is

NANA of #1 and NNNN of time cell #3 are bitwise or, NANA. For another example, assume that the user terminal correctly demodulates TB0 and TB2, and correctly demodulates 1,2 and 4 th coding block groups of TB1 of time unit #1, and also correctly demodulates 3 rd coding block group after receiving TB1 of time unit # 3. But the user terminal finds that the transport block CRC is erroneous, the fed back HARQ-ACK/NACK is aaaaaannnnnann.

Mode two: for the same transmission block, the user terminal sets the HARQ-ACK/NACK values of all received PDSCHs to be the same value, and the value is generated according to the demodulation result of the PDSCH received at the last time. If the user terminal receives a plurality of PDSCHs and finds that the CRC check of all coded blocks is correct but the CRC check of the transport block is incorrect, the user will set the HARQ-ACK/NACK of all PDSCHs to NACK. If the user terminal does not find an error of the CRC check of the transport block, the user terminal generates HARQ-ACK/NACK according to a demodulation result of the PDSCH received last time, and sets the HARQ-ACK/NACK of the PDSCH received before to be the same value as the HARQ-ACK/NACK of the PDSCH received last time. Of course, if the user terminal does not detect the partial PDSCH, but the user finds that there is missed detection of this PDSCH, a NACK is generated.

This has the advantage that if the physical layer or MAC layer can only keep the last demodulated HARQ-ACK information for the same transport block, it is naturally feasible to also keep the last demodulated HARQ-ACK result in the last HARQ-ACK bit position of the last PDSCH. Of course, it is possible that the physical layer may reserve the HARQ-ACK result of the PDSCH for multiple times for the same transport block, but the probability that the base station correctly receives the HARQ-ACK may also be increased by setting the HARQ-ACK for the same transport block, which is transmitted in the same PUCCH or PUSCH, to the same value.

As shown in fig. 18, carrier 1 is configured for HARQ-ACK/NACK feedback based on coding block groups, N1=4. It is assumed that the scheduled PDSCHs shown in the figure all correspond to the same PUCCH feedback HARQ-ACK. The base station schedules the retransmission of transport block TB0 at time unit #0, the base station schedules the initial transmission of transport block TB1 at time unit #1, where the 3 rd CBG is turned off by the URLLC, the base station schedules the retransmission of the 3 rd CBG of transport block TB1 again at time unit #3, and the base station schedules the initial transmission of transport block TB2 at time unit # 2. The feedback mode is assumed to be feedback according to the configured maximum number of coding blocks, i.e. N1=4. Assuming that the user terminal successfully detects the PDCCH of the above 4 time elements scheduling PDSCH, the HARQ-ACKs fed back by the end user terminal are in the order of 4 bits of TB0 of time element #0, 4 bits of TB1 of

time element #

1, 4 bits of TB2 of

time element #

2, and 4 bits of TB1 of time element # 3. It is assumed that the user terminal correctly demodulates TB0 and TB2, and correctly demodulates 2 nd and 4 th coding block groups of TB1 of time unit #1, and also correctly demodulates 3 rd coding block group after receiving TB1 of time unit # 3. According to the method of the present invention, the feedback HARQ-ACK/NACK bit is AAAAAAAAAANAAA, that is, although the HARQ-ACK corresponding to TB1 of time unit #1 is fed back according to the HARQ-ACK of time unit # 3. If the user terminal does not detect the PDCCH of time cell #3, the user terminal should generate a demodulation result when feeding back ACK/NACK for TB1 of time cell #1, i.e., the total HARQ-ACK/NACK bits fed back are aaaaaananaanannn. The base station side can determine whether the user terminal correctly demodulates the corresponding coding block group by bitwise OR of a plurality of HARQ-ACK/NACK of the same TB. For example, in this latter example, the NANA of time cell #1 and the NNNN of time cell #3 are bitwise or' ed to NANA. For another example, assume that the user terminal correctly demodulates TB0 and TB2, and correctly demodulates 1,2 and 4 th coding block groups of TB1 of time unit #1, and also correctly demodulates 3 rd coding block group after receiving TB1 of time unit # 3. But the user terminal finds that the transport block CRC is erroneous, the fed back HARQ-ACK/NACK is aaaaaannnnnann.

In the above example, the last PDSCH described above means that the user terminal can demodulate the PDSCH before feeding back HARQ-ACK on the PUCCH/PUSCH and generate HARQ-ACK according to the demodulation result. Generally, if the base station schedules the HARQ-ACK of the PDSCH to be uploaded on a certain PUCCH or PUSCH, the base station will ensure that the time difference from the PDSCH to the PUCCH/PUSCH is not less than the processing delay of the user terminal, that is, the user terminal has enough time to demodulate the PDSCH and generate the corresponding HARQ-ACK. However, in some implementations, if the time difference is smaller than the processing delay of the user terminal, the HARQ-ACK of such PDSCH can feed back NACK, or duplicate the HARQ-ACK of PDSCH of the previous HARQ-ACK generated according to the demodulation result.

In the above embodiment, the uplink/downlink time unit may be a timeslot or a mini timeslot. For example, the downlink time unit for receiving downlink data is a timeslot, the uplink time unit for HARQ-ACK/NACK feedback is also a timeslot, or the downlink time unit for receiving downlink data is a mini-timeslot, the uplink time unit for HARQ-ACK/NACK feedback is also a mini-timeslot, or the downlink time unit for receiving downlink data is a timeslot, the uplink time unit for HARQ-ACK/NACK feedback is a mini-timeslot, or the downlink time unit for receiving downlink data is a mini-timeslot, and the uplink time unit for HARQ-ACK/NACK feedback is a timeslot. The uplink/downlink time unit can be determined as a timeslot or a mini timeslot through higher layer configuration or a predefined rule, and can also be indicated through dynamic signaling.

The method in the above embodiment may also be applied to the case of carrier aggregation, that is, the base station configures a plurality of serving cells for the user equipment. Correspondingly, when determining the size of the HARQ-ACK/NACK codebook, the method of the present invention is required to determine the number of bits of the HARQ-AC/NACK K of each carrier, and also determine the total number of bits of the HARQ-ACK/NACK and the mapping method according to the configured multiple serving cells. For example, in the second exemplary embodiment of the present invention, the total number of HARQ-ACK/NACK bits of each carrier is determined according to the size of the feedback window, and then the total number of bits of HARQ-ACK/NACK codebooks and HARQ-ACK/NACK bit mapping of all carriers and all downlink time units are determined according to the number of carriers.

In the above embodiment, when it is not determined whether the ue and the base station understand certain configurations, for example, the configuration of HARQ-ACK/NACK feedback, or when the base station has not configured HARQ-ACK/NACK feedback for the user, the base station may communicateThe over-scheduling user terminal works in a backspacing mode to ensure that the base station and the user terminal understand the HARQ-ACK/NACK code book consistently. For example, the base station may schedule the user terminal to operate in the fallback mode before the base station does not transmit the high layer control signaling for determining the HARQ-ACK/NACK codebook, or before the base station does not determine that the user terminal has correctly received the high layer control signaling for determining the HARQ-ACK/NACK codebook. For example, in the first exemplary embodiment, when the base station does not semi-statically configure the HARQ-ACK/NACK codebook size, the base station may implement, through scheduling, feedback of HARQ-ACK/NACK for only one downlink time unit in one uplink time unit, and the user terminal may perform feedback according to HARQ-ACK/NACK for one time unit. For another example, in the third exemplary embodiment, before the base station does not determine that the user terminal has correctly received the high layer control signaling configuring HARQ-ACK/NACK based on the coding block group or the transport block, the base station may schedule HARQ-ACK/NACK of PDSCH of one downlink time unit of one carrier fed back only in one uplink time unit, and schedule downlink control information of the PDSCH in a fallback mode, that is, both the PDSCH scheduled by the scheduling signaling and HARQ-ACK/NACK feedback of the PDSCH are in transport block units. In this way, the user terminal only feeds back N ₂ Bit HARQ-ACK/NACK, e.g. N ₂ =1, and the user terminal may send HARQ-ACK/NACK with PUCCH format for carrying less overhead, e.g. similar to PUCCH format 1a/1b in LTE system. This has the advantage that N in the base station reconfiguration of the coding block group based scheduling/feedback mode or reconfiguration of the coding block group based scheduling/feedback mode ₁ In this case, the user may not be able to determine the overhead of the downlink control signaling or the PUCCH, but the user may determine the overhead of the downlink control signaling in the fallback mode and the overhead of the PUCCH corresponding to the PDSCH scheduled by the downlink control signaling.

Fig. 14 is a flowchart of a downlink transmission method according to the present invention. Here, downlink transmission is performed by the base station.

Referring to fig. 14, a base station configures control signaling in step 1401.

In step 1402, the base station transmits PDSCH and control signaling to the user equipment in downlink time units. Here, the control signaling can be used to determine at least one of the following for user equipment feedback: an uplink time unit of HARQ-ACK/NACK corresponding to PDSCH, the size of HARQ-ACK/NACK code book corresponding to the uplink time unit, and the position of HARQ-ACK/NACK corresponding to each downlink time unit corresponding to the uplink time unit in the HARQ-ACK/NACK code book.

According to an example embodiment, the control signaling may be downlink scheduling signaling carried through a PDCCH or control signaling carried through a PDSCH.

According to an example embodiment, the control signaling may include information about HARQ-ACK/NACK timing.

According to an exemplary embodiment, the information on the HARQ-ACK/NACK timing may be one of the following information: the information indicating the time difference from the downlink time unit where the PDSCH is located to the uplink time unit where the HARQ-ACK/NACK is fed back, the information indicating one or more uplink time units which are larger than or equal to the minimum time difference from the downlink time unit where the PDSCH is located to the uplink time unit where the HARQ-ACK/NACK is fed back and are closest to the minimum time difference, the information indicating the time difference from the downlink time unit where the predefined PDSCH is located to the uplink time unit where the HARQ-ACK/NACK is fed back, the information indicating one or more uplink time units which are larger than or equal to the minimum time difference from the downlink time unit where the PDSCH is located to the uplink time unit where the HARQ-ACK/NACK is fed back and are closest to the minimum time difference, and the information indicating one or more uplink time units which are larger than or equal to the time difference from the downlink time unit where the predefined PDSCH is located to the uplink time unit where the HARQ-ACK/NACK is fed back and are closest to the minimum time difference.

According to an exemplary embodiment, the control signaling may further include a first type of DAI, wherein the first type of DAI indicates one of the following information: relative time sequence of the current scheduled downlink time unit in all the scheduled downlink time units corresponding to the uplink time unit, and bit position of HARQ-ACK/NACK bit of the current scheduled downlink time unit in HARQ-ACK/NACK code book. When the UE is configured to be in the working mode of carrier aggregation, the first type of DAI may be counted by each carrier, for example, the DAI in the downlink control signaling in the existing LTE Rel-8TDD system, or the first type of DAI is counted by each scheduled carrier in the same time unit after frequency, and then counted by each scheduled carrier in the next time unit, for example, the DAI in the downlink control signaling in the existing LTE Rel-13 carrier aggregation system. The first type of DAI can be used for dynamically determining the HARQ-ACK code book and can also be used for semi-statically determining the HARQ-ACK code book.

According to an example embodiment, in the control signaling, the first type of DAI may be jointly encoded with information about HARQ-ACK/NACK timing.

According to an exemplary embodiment, the control signaling may further include a second type of DAI, wherein the second type of DAI indicates one of the following information: the total number of downlink time units of all scheduled downlink time units corresponding to the uplink time unit, the total number of downlink time units from a first downlink time unit to a current downlink time unit in all scheduled downlink time units corresponding to the uplink time unit, and the total bit number of the second-type DAI indication HARQ-ACK/NACK codebook.

According to an exemplary embodiment, in the control signaling, the first type DAI, the second type DAI, and information on HARQ-ACK/NACK timing may be jointly encoded.

According to an example embodiment, the control signaling may further include information indicating that the number of HARQ-ACK/NACK bits corresponding to each downlink time unit is determined according to the number of transport blocks that can be transmitted at most in each downlink time unit, or according to the number of coding block groups that can be transmitted at most in each downlink time unit.

According to an example embodiment, the control signaling may also include a size of a HARQ-ACK/NACK codebook configured by the base station.

According to an exemplary embodiment, the control signaling may further include information indicating a time unit in which the PDSCH is not transmitted with certainty.

According to an exemplary embodiment, when the total number of bits of uplink control signaling at least including HARQ-ACK/NACK, which needs to be fed back in the uplink time unit, exceeds the maximum number of bits of uplink control signaling that can be carried by PUCCH resources configured by the base station, which is accumulated in the current downlink time unit, the base station may send, to the user equipment, new downlink scheduling information of PUCCH resources capable of carrying the total number of bits of the uplink control signaling that needs to be fed back in the current downlink time unit or at least the last downlink time unit corresponding to the uplink time unit.

Fig. 15 is a block diagram of an apparatus 1500 for transmitting HARQ-ACK/NACK according to the present invention. Here, the user equipment can transmit HARQ-ACK/NACK using the apparatus 1500 that transmits HARQ-ACK/NACK.

Referring to fig. 15, an apparatus 1500 for transmitting HARQ-ACK/NACK may include a receiving unit 1501, a determining unit 1502, a generating unit 1503, and a transmitting unit 1504.

Specifically, the receiving unit 1501 may receive PDSCH and control signaling from the base station in downlink time units.

Next, determining unit 1502 may determine, based on the control signaling, an uplink time unit for feeding back HARQ-ACK/NACK corresponding to the received PDSCH, a size of a HARQ-ACK/NACK codebook corresponding to the uplink time unit, and a position of HARQ-ACK/NACK corresponding to each downlink time unit corresponding to the uplink time unit in the HARQ-ACK/NACK codebook.

Next, generation unit 1503 may generate the HARQ-ACK/NACK codebook based on the size of the HARQ-ACK/NACK codebook and the position of the HARQ-ACK/NACK corresponding to each downlink time unit corresponding to the uplink time unit in the HARQ-ACK/NACK codebook.

Finally, a transmission unit 1504 may transmit the generated HARQ-ACK/NACK codebook in an uplink time unit.

The apparatus 1500 transmitting HARQ-ACK/NACK can implement the above-described various exemplary embodiments of the present invention by the reception unit 1501, the determination unit 1502, the generation unit 1503, and the transmission unit 1504. The receiving unit 1501, the determining unit 1502, the generating unit 1503, and the transmitting unit 1504 may respectively implement corresponding functions in the respective embodiments described in detail above, and detailed functions refer to the respective embodiments described above, and detailed descriptions thereof will be omitted here.

Fig. 16 is a block diagram of a downstream transmission device 1600 in accordance with the present invention. Here, the base station can perform downlink transmission using the downlink transmission apparatus 1600 of the present invention.

Referring to fig. 16, the downlink transmission apparatus 1600 may include a configuration unit 1601 and a transmitting unit 1602.

Specifically, the configuration unit 1601 configures the control signaling.

Transmission section 1602 transmits PDSCH and control signaling to user equipment in downlink time units. Here, the control signaling can be used to determine at least one of the following for user equipment feedback: an uplink time unit of HARQ-ACK/NACK corresponding to PDSCH, the size of an HARQ-ACK/NACK codebook corresponding to the uplink time unit, and the position of HARQ-ACK/NACK corresponding to each downlink time unit corresponding to the uplink time unit in the HARQ-ACK/NACK codebook.

According to an exemplary embodiment, the information on the HARQ-ACK/NACK timing may be one of the following information: the information of the time difference from the downlink time unit where the PDSCH is located to the uplink time unit where the HARQ-ACK/NACK is fed back is indicated, the information of the uplink time unit which is larger than or equal to the minimum time difference from the downlink time unit where the PDSCH is located to the uplink time unit where the HARQ-ACK/NACK is fed back and is closest to the minimum time difference is indicated, the information of the time difference from the downlink time unit where the predefined PDSCH is located to the uplink time unit where the HARQ-ACK/NACK is fed back is indicated, and the information of the uplink time unit which is larger than or equal to the time difference from the downlink time unit where the predefined PDSCH is located to the uplink time unit where the HARQ-ACK/NACK is fed back is indicated, and is closest to the uplink time unit or the uplink time unit which contains the configured PUCCH.

According to an exemplary embodiment, the control signaling may further include a first type of DAI, wherein the first type of DAI indicates one of the following information: relative time sequence of the current scheduled downlink time unit in all the scheduled downlink time units corresponding to the uplink time unit, and bit position of HARQ-ACK/NACK bit of the current scheduled downlink time unit in the HARQ-ACK/NACK code book.

According to an exemplary embodiment, the control signaling may further include a size of a HARQ-ACK/NACK codebook configured by the base station.

According to an exemplary embodiment, when the total number of bits of the uplink control signaling at least including HARQ-ACK/NACK, which needs to be fed back in the uplink time unit, exceeds the maximum number of bits of the uplink control signaling that can be carried by the PUCCH resource configured by the base station when the total number of bits is accumulated in the current downlink time unit, the sending unit 1602 may send, to the user equipment, new downlink scheduling information of the PUCCH resource capable of carrying the total number of bits of the uplink control signaling that needs to be fed back in the current downlink time unit or at least the last downlink time unit corresponding to the uplink time unit.

According to the method and the equipment for sending the HARQ-ACK/NACK by the user equipment and the method and the equipment for sending the HARQ by the base station, under the condition that the HARQ-ACK feedback time is variable, the user equipment can accurately judge the size and the bit mapping of the HARQ-ACK code book, and the uplink control channel resources can be effectively utilized.

The foregoing is only a partial embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. A method of transmitting hybrid automatic repeat request-acknowledgement/negative HARQ-ACK/NACK in a communication system, comprising:

determining a first set comprising at least one HARQ-ACK/NACK timing value based on at least one of higher layer signaling or a pre-configuration from a base station;

determining a second set comprising at least one downlink time unit for physical downlink shared channel, PDSCH, reception based on the first set comprising the at least one HARQ-ACK/NACK timing value, wherein HARQ-ACK/NACK information for each downlink time unit comprised in the second set is transmitted in an uplink time unit;

generating a codebook for the HARQ-ACK/NACK information based on a size of the codebook, wherein the size of the codebook is obtained by a size of the second set and one or more HARQ-ACK/NACK bit numbers corresponding to each downlink time unit included in the second set;

transmitting the codebook for the HARQ-ACK/NACK information to the base station in the uplink time unit,

wherein each timing value in the first set indicates a time difference between a respective downlink time unit for PDSCH reception and the uplink time unit for transmitting the codebook.

2. The method of claim 1, wherein the information indicating the time unit in which the PDSCH is not allowed is received via radio resource control, RRC, signaling;

wherein the size of the second set is obtained by removing at least one time unit according to the RRC signaling.

3. The method of claim 1, wherein,

the number of one or more HARQ-ACK/NACK bits corresponding to each downlink time unit is determined based on at least one parameter received from the base station via the higher layer signaling,

wherein the at least one parameter comprises at least one of: maximum number of transport blocks TB in each downlink time unit, maximum number of coding block groups CBG in each downlink time unit.

4. The method of claim 1, wherein the one or more HARQ-ACK/NACK bit numbers corresponding to each downlink time unit are determined based on:

2 bits in case of spatial bundling disabled and scheduling based on transport block TB;

1 bit in case of spatial binding enabled; or

The maximum number of CBGs in one TB in case of scheduling based on coding block group CBGs.

5. The method of claim 1, further comprising:

receiving downlink control information, DCI, from the base station, wherein the DCI includes information indicating one value of the first set,

wherein the one value indicates a time difference between a downlink time unit in which the PDSCH scheduled by the DCI is received and the uplink time unit,

wherein HARQ-ACK/NACK results for the PDSCH are included in the codebook.

6. The method of claim 1, wherein each information bit of the codebook for the HARQ-ACK/NACK information corresponds to each downlink time unit included in the second set.

7. The method of claim 1, wherein each downlink time unit corresponds to a time slot and the uplink time unit corresponds to a time slot.

8. An apparatus for transmitting hybrid automatic repeat request-acknowledgement/negative HARQ-ACK/NACK in a communication system, comprising:

at least one processor configured to:

generating a codebook for the HARQ-ACK/NACK information based on a size of the codebook, wherein the size of the codebook is obtained by a size of the second set and one or more HARQ-ACK/NACK bit numbers corresponding to each downlink time unit included in the second set; and

a transceiver configured to: transmitting the codebook for the HARQ-ACK/NACK information to the base station in the uplink time unit,

9. The apparatus of claim 8, wherein the information indicating the time unit in which the PDSCH is not allowed is received via radio resource control, RRC, signaling;

10. The apparatus of claim 8, wherein,

11. The apparatus of claim 8, wherein the one or more HARQ-ACK/NACK bit numbers corresponding to each downlink time unit are determined based on:

1 bit in case of spatial binding enabled; or

12. The device of claim 8, wherein the at least one processor is further configured to:

wherein HARQ-ACK/NACK results for the PDSCH are included in the codebook.

13. The apparatus of claim 8, wherein each information bit of the codebook for the HARQ-ACK/NACK information corresponds to each downlink time unit included in the second set.

14. The apparatus of claim 8, wherein each downlink time unit corresponds to a time slot and the uplink time unit corresponds to a time slot.

15. An apparatus for receiving hybrid automatic repeat request-acknowledgement/negative HARQ-ACK/NACK in a communication system, comprising:

at least one processor;

a transceiver configured to:

transmitting a Physical Downlink Shared Channel (PDSCH) in a second set comprising at least one downlink time unit, wherein HARQ-ACK/NACK information for each downlink time unit comprised in the second set is transmitted in an uplink time unit;

receiving a codebook for the HARQ-ACK/NACK information at the uplink time unit;

wherein a size of a codebook for the HARQ-ACK/NACK information is associated with a size of the second set and one or more HARQ-ACK/NACK bit numbers corresponding to each downlink time unit included in the second set,

wherein the second set is associated with a first set comprising at least one HARQ-ACK/NACK timing value,

wherein the first set is determined based on at least one of higher layer signaling or a pre-configuration transmitted from the apparatus,

16. The apparatus of claim 15, wherein the information indicating the time unit in which the PDSCH is not allowed is transmitted via Radio Resource Control (RRC) signaling,

17. The apparatus of claim 15, wherein a number of HARQ-ACK/NACK bits corresponding to each downlink time unit is associated with at least one parameter of the higher layer signaling,